diff --git a/src/propedit/attachment_target.cpp b/src/propedit/attachment_target.cpp
index 0c967dbb5..cb8709d7f 100644
--- a/src/propedit/attachment_target.cpp
+++ b/src/propedit/attachment_target.cpp
@@ -63,35 +63,35 @@ attachment_target_c::validate() {
   try {
     m_file_content = mm_file_io_c::slurp(m_file_name);
   } catch (mtx::mm_io::exception &ex) {
-    mxerror(boost::format(Y("The file '%1%' could not be opened for reading: %2%.\n")) % m_file_name % ex.what());
+    mxerror(fmt::format(Y("The file '{0}' could not be opened for reading: {1}.\n"), m_file_name, ex.what()));
   }
 }
 
 void
 attachment_target_c::dump_info()
   const {
-  mxinfo(boost::format("  attachment target:\n"
-                       "    file_name: %1%\n"
-                       "    command: %2% (%3%)\n"
-                       "    options: %4%\n"
-                       "    selector_type: %5% (%6%)\n"
-                       "    selector_num_arg: %7%\n"
-                       "    selector_string_arg: %8%\n")
-         % m_file_name
-         % m_command
-         % (  ac_add     == m_command ? "add"
-            : ac_delete  == m_command ? "delete"
-            : ac_replace == m_command ? "replace"
-            : ac_update  == m_command ? "update"
-            :                           "unknown")
-         % m_options
-         % m_selector_type
-         % (  st_id        == m_selector_type ? "ID"
-            : st_uid       == m_selector_type ? "UID"
-            : st_name      == m_selector_type ? "name"
-            : st_mime_type == m_selector_type ? "MIME type"
-            :                                   "unknown")
-         % m_selector_num_arg % m_selector_string_arg);
+  mxinfo(fmt::format("  attachment target:\n"
+                     "    file_name: {0}\n"
+                     "    command: {1} ({2})\n"
+                     "    options: {3}\n"
+                     "    selector_type: {4} ({5})\n"
+                     "    selector_num_arg: {6}\n"
+                     "    selector_string_arg: {7}\n",
+                     m_file_name,
+                     m_command,
+                       ac_add     == m_command ? "add"
+                     : ac_delete  == m_command ? "delete"
+                     : ac_replace == m_command ? "replace"
+                     : ac_update  == m_command ? "update"
+                     :                           "unknown",
+                     m_options,
+                     m_selector_type,
+                       st_id        == m_selector_type ? "ID"
+                     : st_uid       == m_selector_type ? "UID"
+                     : st_name      == m_selector_type ? "name"
+                     : st_mime_type == m_selector_type ? "MIME type"
+                     :                                   "unknown",
+                     m_selector_num_arg, m_selector_string_arg));
 }
 
 bool
@@ -201,7 +201,7 @@ attachment_target_c::execute_delete() {
   bool deleted_something = st_id == m_selector_type ? delete_by_id() : delete_by_uid_name_mime_type();
 
   if (!deleted_something)
-    mxwarn(boost::format(Y("No attachment matched the spec '%1%'.\n")) % m_spec);
+    mxwarn(fmt::format(Y("No attachment matched the spec '{0}'.\n"), m_spec));
 
   else
     m_attachments_modified = true;
@@ -212,7 +212,7 @@ attachment_target_c::execute_replace() {
   bool replaced_something = st_id == m_selector_type ? replace_by_id() : replace_by_uid_name_mime_type();
 
   if (!replaced_something)
-    mxwarn(boost::format(Y("No attachment matched the spec '%1%'.\n")) % m_spec);
+    mxwarn(fmt::format(Y("No attachment matched the spec '{0}'.\n"), m_spec));
 
   else
     m_attachments_modified = true;
diff --git a/src/propedit/change.cpp b/src/propedit/change.cpp
index 367cc896d..83868eff7 100644
--- a/src/propedit/change.cpp
+++ b/src/propedit/change.cpp
@@ -50,7 +50,7 @@ change_c::change_c(change_c::change_type_e type,
 void
 change_c::validate() {
   if (m_property.m_name.empty())
-    mxerror(boost::format(Y("The name '%1%' is not a valid property name for the current edit specification in '%2%'.\n")) % m_name % get_spec());
+    mxerror(fmt::format(Y("The name '{0}' is not a valid property name for the current edit specification in '{1}'.\n"), m_name, get_spec()));
 
   if (change_c::ct_delete == m_type)
     validate_deletion_of_mandatory();
@@ -60,21 +60,21 @@ change_c::validate() {
 
 std::string
 change_c::get_spec() {
-  return change_c::ct_delete == m_type ? (boost::format("--delete %1%")                                                 % m_name          ).str()
-       :                                 (boost::format("--%1% %2%=%3%") % (change_c::ct_add == m_type ? "add" : "set") % m_name % m_value).str();
+  return change_c::ct_delete == m_type ? fmt::format("--delete {0}",                                                 m_name          )
+       :                                 fmt::format("--{0} {1}={2}", change_c::ct_add == m_type ? "add" : "set", m_name, m_value);
 }
 
 void
 change_c::dump_info()
   const
 {
-  mxinfo(boost::format("    change:\n"
-                       "      type:  %1%\n"
-                       "      name:  %2%\n"
-                       "      value: %3%\n")
-         % static_cast<int>(m_type)
-         % m_name
-         % m_value);
+  mxinfo(fmt::format("    change:\n"
+                     "      type:  {0}\n"
+                     "      name:  {1}\n"
+                     "      value: {2}\n",
+                     static_cast<int>(m_type),
+                     m_name,
+                     m_value));
 }
 
 bool
@@ -108,7 +108,7 @@ change_c::parse_ascii_string() {
   size_t i;
   for (i = 0; m_value.length() > i; ++i)
     if (127 < static_cast<unsigned char>(m_value[i]))
-      mxerror(boost::format(Y("The property value contains non-ASCII characters, but the property is not a Unicode string in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+      mxerror(fmt::format(Y("The property value contains non-ASCII characters, but the property is not a Unicode string in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
 
   m_s_value = m_value;
 }
@@ -121,13 +121,13 @@ change_c::parse_unicode_string() {
 void
 change_c::parse_unsigned_integer() {
   if (!parse_number(m_value, m_ui_value))
-    mxerror(boost::format(Y("The property value is not a valid unsigned integer in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("The property value is not a valid unsigned integer in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
 }
 
 void
 change_c::parse_signed_integer() {
   if (!parse_number(m_value, m_si_value))
-    mxerror(boost::format(Y("The property value is not a valid signed integer in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("The property value is not a valid signed integer in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
 }
 
 void
@@ -135,14 +135,14 @@ change_c::parse_boolean() {
   try {
     m_b_value = parse_bool(m_value);
   } catch (...) {
-    mxerror(boost::format(Y("The property value is not a valid boolean in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("The property value is not a valid boolean in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
   }
 }
 
 void
 change_c::parse_floating_point_number() {
   if (!parse_number(m_value, m_fp_value))
-    mxerror(boost::format(Y("The property value is not a valid floating point number in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("The property value is not a valid floating point number in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
 }
 
 void
@@ -151,8 +151,8 @@ change_c::parse_binary() {
     m_x_value = mtx::bits::value_c(m_value, m_property.m_bit_length);
   } catch (...) {
     if (m_property.m_bit_length)
-      mxerror(boost::format(Y("The property value is not a valid binary spec or it is not exactly %3% bits long in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED % m_property.m_bit_length);
-    mxerror(boost::format(Y("The property value is not a valid binary spec in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+      mxerror(fmt::format(Y("The property value is not a valid binary spec or it is not exactly {2} bits long in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED, m_property.m_bit_length));
+    mxerror(fmt::format(Y("The property value is not a valid binary spec in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
   }
 }
 
@@ -215,11 +215,11 @@ change_c::parse_date_time() {
     }
   }
 
-  mxerror(boost::format("%1% %2% %3% %4%\n")
-          % (boost::format(Y("The property value is not a valid date & time string in '%1%'.")) % get_spec()).str()
-          % Y("The recognized format is 'YYYY-mm-ddTHH:MM:SS+zz:zz': the year, month, day, letter 'T', hours, minutes, seconds and the time zone's offset from UTC; example: 2017-03-28T17:28-02:00.")
-          % Y("The letter 'Z' can be used instead of the time zone's offset from UTC to indicate UTC aka Zulu time.")
-          % FILE_NOT_MODIFIED);
+  mxerror(fmt::format("{0} {1} {2} {3}\n",
+                      fmt::format(Y("The property value is not a valid date & time string in '{0}'."), get_spec()),
+                      Y("The recognized format is 'YYYY-mm-ddTHH:MM:SS+zz:zz': the year, month, day, letter 'T', hours, minutes, seconds and the time zone's offset from UTC; example: 2017-03-28T17:28-02:00."),
+                      Y("The letter 'Z' can be used instead of the time zone's offset from UTC to indicate UTC aka Zulu time."),
+                      FILE_NOT_MODIFIED));
 }
 
 void
@@ -253,7 +253,7 @@ change_c::execute_delete() {
   }
 
   if (1 < verbose)
-    mxinfo(boost::format(Y("Change for '%1%' executed. Number of entries deleted: %2%\n")) % get_spec() % num_deleted);
+    mxinfo(fmt::format(Y("Change for '{0}' executed. Number of entries deleted: {1}\n"), get_spec(), num_deleted));
 }
 
 void
@@ -273,24 +273,24 @@ change_c::execute_add_or_set() {
   if (0 == num_found) {
     do_add_element();
     if (1 < verbose)
-      mxinfo(boost::format(Y("Change for '%1%' executed. No property of this type found. One entry added.\n")) % get_spec());
+      mxinfo(fmt::format(Y("Change for '{0}' executed. No property of this type found. One entry added.\n"), get_spec()));
     return;
   }
 
   if (change_c::ct_set == m_type) {
     if (1 < verbose)
-      mxinfo(boost::format(Y("Change for '%1%' executed. Number of entries set: %2%.\n")) % get_spec() % num_found);
+      mxinfo(fmt::format(Y("Change for '{0}' executed. Number of entries set: {1}.\n"), get_spec(), num_found));
     return;
   }
 
   const EbmlSemantic *semantic = get_semantic();
   if (semantic && semantic->Unique)
-    mxerror(boost::format(Y("This property is unique. More instances cannot be added in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("This property is unique. More instances cannot be added in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
 
   do_add_element();
 
  if (1 < verbose)
-    mxinfo(boost::format(Y("Change for '%1%' executed. One entry added.\n")) % get_spec());
+    mxinfo(fmt::format(Y("Change for '{0}' executed. One entry added.\n"), get_spec()));
 }
 
 void
@@ -329,7 +329,7 @@ change_c::validate_deletion_of_mandatory() {
   std::unique_ptr<EbmlElement> elt(&semantic->Create());
 
   if (!elt->DefaultISset())
-    mxerror(boost::format(Y("This property is mandatory and cannot be deleted in '%1%'. %2%\n")) % get_spec() % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("This property is mandatory and cannot be deleted in '{0}'. {1}\n"), get_spec(), FILE_NOT_MODIFIED));
 }
 
 const EbmlSemantic *
@@ -360,7 +360,7 @@ change_c::parse_spec(change_c::change_type_e type,
       && (name == "language")) {
     auto idx = map_to_iso639_2_code(value);
     if (-1 == idx)
-      throw std::runtime_error{(boost::format(("invalid ISO 639-2 language code '%1%'")) % value).str()};
+      throw std::runtime_error{fmt::format(("invalid ISO 639-2 language code '{0}'"), value)};
 
     value = g_iso639_languages[idx].iso639_2_code;
   }
diff --git a/src/propedit/chapter_target.cpp b/src/propedit/chapter_target.cpp
index fcd3dc35e..7aef13ba2 100644
--- a/src/propedit/chapter_target.cpp
+++ b/src/propedit/chapter_target.cpp
@@ -41,9 +41,9 @@ chapter_target_c::validate() {
 void
 chapter_target_c::dump_info()
   const {
-  mxinfo(boost::format("  chapter target:\n"
-                       "    file_name: %1%\n")
-         % m_file_name);
+  mxinfo(fmt::format("  chapter target:\n"
+                     "    file_name: {0}\n",
+                     m_file_name));
 }
 
 bool
@@ -66,7 +66,7 @@ chapter_target_c::execute() {
 
   fix_mandatory_elements(m_level1_element);
   if (!m_level1_element->CheckMandatory())
-    mxerror(boost::format(Y("Error parsing the chapters in '%1%': some mandatory elements are missing.\n")) % m_file_name);
+    mxerror(fmt::format(Y("Error parsing the chapters in '{0}': some mandatory elements are missing.\n"), m_file_name));
 
   if (m_analyzer->is_webm())
     mtx::chapters::remove_elements_unsupported_by_webm(*m_level1_element);
diff --git a/src/propedit/options.cpp b/src/propedit/options.cpp
index 20f0f1237..abee777a9 100644
--- a/src/propedit/options.cpp
+++ b/src/propedit/options.cpp
@@ -127,7 +127,7 @@ options_c::add_delete_track_statistics_tags(tag_target_c::tag_operation_mode_e o
 void
 options_c::set_file_name(const std::string &file_name) {
   if (!m_file_name.empty())
-    mxerror(boost::format(Y("More than one file name has been given ('%1%' and '%2%').\n")) % m_file_name % file_name);
+    mxerror(fmt::format(Y("More than one file name has been given ('{0}' and '{1}').\n"), m_file_name, file_name));
 
   m_file_name = file_name;
 }
@@ -148,13 +148,13 @@ void
 options_c::dump_info()
   const
 {
-  mxinfo(boost::format("options:\n"
-                       "  file_name:     %1%\n"
-                       "  show_progress: %2%\n"
-                       "  parse_mode:    %3%\n")
-         % m_file_name
-         % m_show_progress
-         % static_cast<int>(m_parse_mode));
+  mxinfo(fmt::format("options:\n"
+                     "  file_name:     {0}\n"
+                     "  show_progress: {1}\n"
+                     "  parse_mode:    {2}\n",
+                     m_file_name,
+                     m_show_progress,
+                     static_cast<int>(m_parse_mode)));
 
   for (auto &target : m_targets)
     target->dump_info();
@@ -183,7 +183,7 @@ read_element(kax_analyzer_c *analyzer,
     e = analyzer->read_element(index);
 
   if (require_existance && (!e || !dynamic_cast<T *>(e.get())))
-    mxerror(boost::format(Y("Modification of properties in the section '%1%' was requested, but no corresponding level 1 element was found in the file. %2%\n")) % category % FILE_NOT_MODIFIED);
+    mxerror(fmt::format(Y("Modification of properties in the section '{0}' was requested, but no corresponding level 1 element was found in the file. {1}\n"), category, FILE_NOT_MODIFIED));
 
   return e;
 }
@@ -263,8 +263,8 @@ options_c::merge_targets() {
 
     existing_target_it->second->merge_changes(*track_target);
 
-    mxwarn(boost::format(Y("The edit specifications '%1%' and '%2%' resolve to the same track with the UID %3%.\n"))
-           % existing_target_it->second->get_spec() % track_target->get_spec() % track_uid);
+    mxwarn(fmt::format(Y("The edit specifications '{0}' and '{1}' resolve to the same track with the UID {2}.\n"),
+                       existing_target_it->second->get_spec(), track_target->get_spec(), track_uid));
   }
 
   m_targets.swap(targets_to_keep);
diff --git a/src/propedit/propedit.cpp b/src/propedit/propedit.cpp
index f067c9c85..6a8b3567a 100644
--- a/src/propedit/propedit.cpp
+++ b/src/propedit/propedit.cpp
@@ -30,7 +30,7 @@ std::unique_ptr<mtx::doc_type_version_handler_c> g_doc_type_version_handler;
 static void
 display_update_element_result(const EbmlCallbacks &callbacks,
                               kax_analyzer_c::update_element_result_e result) {
-  std::string message((boost::format(Y("Updating the '%1%' element failed. Reason:")) % callbacks.DebugName).str());
+  std::string message(fmt::format(Y("Updating the '{0}' element failed. Reason:"), callbacks.DebugName));
   message += " ";
 
   switch (result) {
@@ -47,24 +47,24 @@ display_update_element_result(const EbmlCallbacks &callbacks,
       break;
 
     case kax_analyzer_c::uer_error_opening_for_reading:
-      message += (boost::format("%1% %2%")
-                  % Y("The file could not be opened for reading.")
-                  % Y("Possible reasons are: the file is not a Matroska file; the file is write-protected; the file is locked by another process; you do not have permission to access the file.")).str();
+      message += fmt::format("{0} {1}",
+                             Y("The file could not be opened for reading."),
+                             Y("Possible reasons are: the file is not a Matroska file; the file is write-protected; the file is locked by another process; you do not have permission to access the file."));
       break;
 
     case kax_analyzer_c::uer_error_opening_for_writing:
-      message += (boost::format("%1% %2%")
-                  % Y("The file could not be opened for writing.")
-                  % Y("Possible reasons are: the file is not a Matroska file; the file is write-protected; the file is locked by another process; you do not have permission to access the file.")).str();
+      message += fmt::format("{0} {1}",
+                             Y("The file could not be opened for writing."),
+                             Y("Possible reasons are: the file is not a Matroska file; the file is write-protected; the file is locked by another process; you do not have permission to access the file."));
       break;
 
     case kax_analyzer_c::uer_error_fixing_last_element_unknown_size_failed:
-      message += (boost::format("%1% %2% %3% %4% %5%")
-                  % Y("The Matroska file's last element is set to an unknown size.")
-                  % Y("Due to the particular structure of the file this situation cannot be fixed automatically.")
-                  % Y("The file can be fixed by multiplexing it with mkvmerge again.")
-                  % Y("The process will be aborted.")
-                  % Y("The file has not been modified.")).str();
+      message += fmt::format("{0} {1} {2} {3} {4}",
+                             Y("The Matroska file's last element is set to an unknown size."),
+                             Y("Due to the particular structure of the file this situation cannot be fixed automatically."),
+                             Y("The file can be fixed by multiplexing it with mkvmerge again."),
+                             Y("The process will be aborted."),
+                             Y("The file has not been modified."));
       break;
 
     default:
@@ -99,7 +99,7 @@ write_changes(options_cptr &options,
       if (id_to_write != l1_element.Generic().GlobalId)
         continue;
 
-      mxverb(2, boost::format(Y("Element %1% is written.\n")) % l1_element.Generic().DebugName);
+      mxverb(2, fmt::format(Y("Element {0} is written.\n"), l1_element.Generic().DebugName));
 
       auto result = l1_element.ListSize() ? analyzer->update_element(&l1_element, target->write_elements_set_to_default_value(), target->add_mandatory_elements_if_missing())
                   :                         analyzer->remove_elements(EbmlId(l1_element));
@@ -121,7 +121,7 @@ update_ebml_head(mm_io_c &file) {
                : mtx::doc_type_version_handler_c::update_result_e::err_not_enough_space == result ? Y("There's not enough space at the beginning of the file to fit the updated 'EBML head' element in.")
                :                                                                                    Y("A generic read or write failure occurred.");
 
-  mxwarn(boost::format("%1% %2%\n") % Y("Updating the 'document type version' or 'document type read version' header fields failed.") % details);
+  mxwarn(fmt::format("{0} {1}\n", Y("Updating the 'document type version' or 'document type read version' header fields failed."), details));
 }
 
 static void
@@ -132,14 +132,14 @@ run(options_cptr &options) {
 
   try {
     if (!kax_analyzer_c::probe(options->m_file_name))
-      mxerror(boost::format("The file '%1%' is not a Matroska file or it could not be found.\n") % options->m_file_name);
+      mxerror(fmt::format(Y("The file '{0}' is not a Matroska file or it could not be found.\n"), options->m_file_name));
 
     analyzer = console_kax_analyzer_cptr(new console_kax_analyzer_c(options->m_file_name));
   } catch (mtx::mm_io::exception &ex) {
-    mxerror(boost::format("The file '%1%' could not be opened for reading and writing: %1.\n") % options->m_file_name % ex);
+    mxerror(fmt::format(Y("The file '{0}' could not be opened for reading and writing: {1}.\n"), options->m_file_name, ex));
   }
 
-  mxinfo(boost::format("%1%\n") % Y("The file is being analyzed."));
+  mxinfo(fmt::format("{0}\n", Y("The file is being analyzed.")));
 
   analyzer->set_show_progress(options->m_show_progress);
 
@@ -152,7 +152,7 @@ run(options_cptr &options) {
       .set_doc_type_version_handler(g_doc_type_version_handler.get())
       .process();
   } catch (mtx::exception &ex) {
-    mxerror(boost::format(Y("The file '%1%' could not be opened for reading and writing, or a read/write operation on it failed: %2%.\n")) % options->m_file_name % ex);
+    mxerror(fmt::format(Y("The file '{0}' could not be opened for reading and writing, or a read/write operation on it failed: {1}.\n"), options->m_file_name, ex));
   } catch (...) {
   }
 
diff --git a/src/propedit/propedit_cli_parser.cpp b/src/propedit/propedit_cli_parser.cpp
index 40542e7d5..409e5ec2d 100644
--- a/src/propedit/propedit_cli_parser.cpp
+++ b/src/propedit/propedit_cli_parser.cpp
@@ -31,7 +31,7 @@ propedit_cli_parser_c::set_parse_mode() {
   try {
     m_options->set_parse_mode(m_next_arg);
   } catch (...) {
-    mxerror(boost::format(Y("Unknown parse mode in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Unknown parse mode in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -40,7 +40,7 @@ propedit_cli_parser_c::add_target() {
   try {
     m_target = m_options->add_track_or_segmentinfo_target(m_next_arg);
   } catch (...) {
-    mxerror(boost::format(Y("Invalid selector in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Invalid selector in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -52,7 +52,7 @@ propedit_cli_parser_c::add_change() {
                                  :                                                         change_c::ct_delete;
     m_target->add_change(type, m_next_arg);
   } catch (std::runtime_error &error) {
-    mxerror(boost::format(Y("Invalid change spec (%3%) in '%1% %2%'.\n")) % m_current_arg % m_next_arg % error.what());
+    mxerror(fmt::format(Y("Invalid change spec ({2}) in '{0} {1}'.\n"), m_current_arg, m_next_arg, error.what()));
   }
 }
 
@@ -61,7 +61,7 @@ propedit_cli_parser_c::add_tags() {
   try {
     m_options->add_tags(m_next_arg);
   } catch (...) {
-    mxerror(boost::format(Y("Invalid selector in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Invalid selector in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -70,7 +70,7 @@ propedit_cli_parser_c::add_chapters() {
   try {
     m_options->add_chapters(m_next_arg);
   } catch (...) {
-    mxerror(boost::format(Y("Invalid selector in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Invalid selector in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -93,7 +93,7 @@ void
 propedit_cli_parser_c::set_attachment_uid() {
   auto uid = uint64_t{};
   if (!parse_number(m_next_arg, uid))
-    mxerror(boost::format(Y("The value '%1%' is not a number.\n")) % m_next_arg);
+    mxerror(fmt::format(Y("The value '{0}' is not a number.\n"), m_next_arg));
 
   m_attachment.m_uid.reset(uid);
 }
@@ -104,7 +104,7 @@ propedit_cli_parser_c::add_attachment() {
     m_options->add_attachment_command(attachment_target_c::ac_add, m_next_arg, m_attachment);
     m_attachment = attachment_target_c::options_t();
   } catch (...) {
-    mxerror(boost::format(Y("Invalid selector in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Invalid selector in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -113,7 +113,7 @@ propedit_cli_parser_c::delete_attachment() {
   try {
     m_options->add_attachment_command(attachment_target_c::ac_delete, m_next_arg, m_attachment);
   } catch (...) {
-    mxerror(boost::format(Y("Invalid selector in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Invalid selector in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -123,7 +123,7 @@ propedit_cli_parser_c::replace_attachment() {
     m_options->add_attachment_command(m_current_arg == "--update-attachment" ? attachment_target_c::ac_update : attachment_target_c::ac_replace, m_next_arg, m_attachment);
     m_attachment = attachment_target_c::options_t();
   } catch (...) {
-    mxerror(boost::format(Y("Invalid selector in '%1% %2%'.\n")) % m_current_arg % m_next_arg);
+    mxerror(fmt::format(Y("Invalid selector in '{0} {1}'.\n"), m_current_arg, m_next_arg));
   }
 }
 
@@ -179,17 +179,16 @@ propedit_cli_parser_c::list_property_names_for_table(const std::vector<property_
   auto max_name_len = boost::accumulate(table, 0u, [](size_t a, const property_element_c &e) { return std::max(a, e.m_name.length()); });
 
   static boost::regex s_newline_re("\\s*\\n\\s*", boost::regex::perl);
-  boost::format format((boost::format("%%|1$-%1%s| | %%|2$-2s| |") % max_name_len).str());
   std::string indent_string = std::string(max_name_len, ' ') + " |    | ";
 
   mxinfo("\n");
-  mxinfo(boost::format(Y("Elements in the category '%1%' ('--edit %2%'):\n")) % title % edit_spec);
+  mxinfo(fmt::format(Y("Elements in the category '{0}' ('--edit {1}'):\n"), title, edit_spec));
 
   for (auto &property : table) {
-    std::string name        = (format % property.m_name % ebml_type_map[property.m_type]).str();
-    std::string description = property.m_title.get_translated()
-                            + ": "
-                            + boost::regex_replace(property.m_description.get_translated(), s_newline_re, " ",  boost::match_default | boost::match_single_line);
+    auto name        = fmt::format("{0:<{1}} | {2:<2} |", property.m_name, max_name_len, ebml_type_map[property.m_type]);
+    auto description = property.m_title.get_translated()
+                     + ": "
+                     + boost::regex_replace(property.m_description.get_translated(), s_newline_re, " ",  boost::match_default | boost::match_single_line);
     mxinfo(format_paragraph(description, max_name_len + 8, name, indent_string));
   }
 }
diff --git a/src/propedit/segment_info_target.cpp b/src/propedit/segment_info_target.cpp
index c77309cf1..09665f966 100644
--- a/src/propedit/segment_info_target.cpp
+++ b/src/propedit/segment_info_target.cpp
@@ -58,7 +58,7 @@ segment_info_target_c::add_change(change_c::change_type_e type,
 void
 segment_info_target_c::dump_info()
   const {
-  mxinfo(boost::format("  segment_info_target:\n"));
+  mxinfo(fmt::format("  segment_info_target:\n"));
 
   for (auto &change : m_changes)
     change->dump_info();
diff --git a/src/propedit/tag_target.cpp b/src/propedit/tag_target.cpp
index f12fa0334..46187d28c 100644
--- a/src/propedit/tag_target.cpp
+++ b/src/propedit/tag_target.cpp
@@ -100,19 +100,19 @@ void
 tag_target_c::dump_info()
   const
 {
-  mxinfo(boost::format("  tag_target:\n"
-                       "    operation_mode:       %1%\n"
-                       "    selection_mode:       %2%\n"
-                       "    selection_param:      %3%\n"
-                       "    selection_track_type: %4%\n"
-                       "    track_uid:            %5%\n"
-                       "    file_name:            %6%\n")
-         % static_cast<int>(m_operation_mode)
-         % static_cast<int>(m_selection_mode)
-         % m_selection_param
-         % m_selection_track_type
-         % m_track_uid
-         % m_file_name);
+  mxinfo(fmt::format("  tag_target:\n"
+                     "    operation_mode:       {0}\n"
+                     "    selection_mode:       {1}\n"
+                     "    selection_param:      {2}\n"
+                     "    selection_track_type: {3}\n"
+                     "    track_uid:            {4}\n"
+                     "    file_name:            {5}\n",
+                     static_cast<int>(m_operation_mode),
+                     static_cast<int>(m_selection_mode),
+                     m_selection_param,
+                     m_selection_track_type,
+                     m_track_uid,
+                     m_file_name));
 
   for (auto &change : m_changes)
     change->dump_info();
@@ -168,7 +168,7 @@ tag_target_c::execute() {
 
   fix_mandatory_elements(m_level1_element);
   if (!m_level1_element->CheckMandatory())
-    mxerror(boost::format(Y("Error parsing the tags in '%1%': some mandatory elements are missing.\n")) % m_file_name);
+    mxerror(fmt::format(Y("Error parsing the tags in '{0}': some mandatory elements are missing.\n"), m_file_name));
 
   if (m_analyzer->is_webm())
     mtx::tags::remove_elements_unsupported_by_webm(*m_level1_element);
@@ -351,7 +351,7 @@ tag_target_c::account_all_clusters() {
   file.setFilePointer(m_analyzer->get_segment_data_start_pos());
 
   mxinfo(Y("The file is read in order to create track statistics.\n"));
-  mxinfo(boost::format(Y("Progress: %1%%%%2%")) % 0 % "\r");
+  mxinfo(fmt::format(Y("Progress: {0}%{1}"), 0, "\r"));
 
   while (true) {
     auto cluster = kax_file->read_next_cluster();
@@ -364,12 +364,12 @@ tag_target_c::account_all_clusters() {
 
     auto current_progress = std::lround(file.getFilePointer() * 100ull / static_cast<double>(file_size));
     if (current_progress != previous_progress) {
-      mxinfo(boost::format(Y("Progress: %1%%%%2%")) % current_progress % "\r");
+      mxinfo(fmt::format(Y("Progress: {0}%{1}"), current_progress, "\r"));
       previous_progress = current_progress;
     }
   }
 
-  mxinfo(boost::format(Y("Progress: %1%%%%2%")) % 100 % "\n");
+  mxinfo(fmt::format(Y("Progress: {0}%{1}"), 100, "\n"));
 }
 
 void
diff --git a/src/propedit/track_target.cpp b/src/propedit/track_target.cpp
index 46bf2226c..9ee568a04 100644
--- a/src/propedit/track_target.cpp
+++ b/src/propedit/track_target.cpp
@@ -69,17 +69,17 @@ track_target_c::add_change(change_c::change_type_e type,
 void
 track_target_c::dump_info()
   const {
-  mxinfo(boost::format("  track_target:\n"
-                       "    selection_mode:       %1%\n"
-                       "    selection_param:      %2%\n"
-                       "    selection_track_type: %3%\n"
-                       "    track_uid:            %4%\n"
-                       "    file_name:            %5%\n")
-         % static_cast<int>(m_selection_mode)
-         % m_selection_param
-         % m_selection_track_type
-         % m_track_uid
-         % m_file_name);
+  mxinfo(fmt::format("  track_target:\n"
+                     "    selection_mode:       {0}\n"
+                     "    selection_param:      {1}\n"
+                     "    selection_track_type: {2}\n"
+                     "    track_uid:            {3}\n"
+                     "    file_name:            {4}\n",
+                     static_cast<int>(m_selection_mode),
+                     m_selection_param,
+                     m_selection_track_type,
+                     m_track_uid,
+                     m_file_name));
 
   for (auto &change : m_changes)
     change->dump_info();
@@ -196,7 +196,7 @@ track_target_c::set_level1_element(ebml_element_cptr level1_element_cp,
     return;
   }
 
-  mxerror(boost::format(Y("No track corresponding to the edit specification '%1%' was found. %2%\n")) % m_spec % FILE_NOT_MODIFIED);
+  mxerror(fmt::format(Y("No track corresponding to the edit specification '{0}' was found. {1}\n"), m_spec, FILE_NOT_MODIFIED));
 }
 
 void