Subtitle Edit is a free (open source) editor for video subtitles - a subtitle editor.

With SE you can easily adjust a subtitle if it is out of sync with the video in several different ways.
You can also use SE for making new subtitles from scratch (do use the time-line/waveform/spectrogram) or translating subtitles.

Features

• Create/adjust/sync/translate subtitle lines
• Convert between SubRib, MicroDVD, Advanced Sub Station Alpha, Sub Station Alpha, D-Cinema, SAMI, youtube sbv, and many more (300+ different formats!)
• Cool audio visualizer control - can display wave form and/or spectrogram
• Video player uses mpv, DirectShow, or VLC media player
• Visually sync/adjust a subtitle (start/end position and speed)
• Audio to text (speech recognition) via Vosk/Kaldi
• Auto Translation via Google translate
• Rip subtitles from a (decrypted) dvd
• Import and OCR VobSub sub/idx binary subtitles
• Import and OCR Blu-ray .sup files - bd sup reading is based on Java code from BDSup2Sub by 0xdeadbeef)
• Can open subtitles embedded inside Matroska files
• Can open subtitles (text, closed captions, VobSub) embedded inside mp4/mv4 files
• Can open/OCR XSub subtitles embedded inside divx/avi files
• Can open/OCR DVB and teletext subtitles embedded inside .ts/.m2ts (Transport Stream) files
• Can open/OCR Blu-ray subtitles embedded inside .m2ts (Transport Stream) files
• Can read and write both UTF-8 and other unicode files and ANSI (support for all languages/encodings on the pc!)
• Sync: Show texts earlier/later + point synchronization + synchronization via other subtitle
• Merge/split subtitles
• Adjust display time
• Fix common errors wizard
• Spell checking via Libre Office dictionaries (many dictionaries available)
• Remove text for hear impaired (HI)
• Renumbering
• Effects: Typewriter and karaoke
• History/undo manager (Undo=Ctrl+z, Redo=Ctrl+y)
• Compare subtitles
• Multiple search and replace
• Change casing using names dictionary
• Merge short lines/split long lines
• Export to PNG images (+bdn xml), Adobe Encore FAB image script, VobSub, Blu-ray sup, EBU stl, PAC, and plain text