15 free online tools for captions and subtitles
Every tool runs entirely in your browser. No uploads, no accounts, no waiting. Upload a file, process it, and download the result — instantly.
Timing & Editing
Fix sync issues and combine multiple subtitle files.
SRT Timing Adjuster
PopularShift every timestamp in an SRT file earlier or later by a fixed number of seconds. The fastest way to fix captions that are consistently out of sync.
SRT Merger
Combine two SRT files into one. The second file's timestamps are automatically offset to follow the first — no manual calculation needed.
Format Conversion
Convert subtitle files between every major format. All processing happens in your browser — nothing is uploaded.
SRT to VTT
Most usedConvert SRT subtitle files into WebVTT format for HTML5 video players, YouTube, and web platforms.
VTT to SRT
Convert WebVTT caption files back into SRT format for video editors, uploaders, and broadcast delivery.
SRT to ASS
Convert SRT files into ASS (Advanced SubStation Alpha) format for advanced caption styling in media players and editors.
SRT to TXT
Strip timestamps and cue numbers from an SRT file and extract the plain text transcript.
SRT to JSON
Convert SRT subtitle cues into structured JSON with start time, end time, and text fields for developers and data pipelines.
VTT to TXT
Extract plain text from WebVTT caption files, removing all timing markers and metadata.
SRT to MP4
Render an SRT file as a subtitle overlay MP4 for importing into editors that don't support direct SRT tracks.
Caption Generation
Generate synced captions from audio. Upload an audio or video file and download a ready-to-use SRT.
Podcast to Captions
Upload an MP3 or podcast audio file and generate a timed SRT caption file. Useful for creating transcripts and captions for long-form audio content.
Lyrics to Captions
Sync song lyrics to audio and export a timed SRT or VTT caption file for music videos and lyric videos.
Suno Lyrics Captions
Add synced captions to Suno AI-generated songs. Upload your Suno audio and export SRT or VTT for sharing.
Free Subtitle Generator
NewUpload any audio or video file and download an SRT subtitle file instantly. No account required. Also translates — pick a different output language to translate your subtitles.
AI Subtitle Generator
NewAI-powered subtitle generation in 57 languages. Upload audio or video and get an SRT in seconds — or pick a different output language to translate.
YouTube Subtitle Generator
NewGenerate an SRT file ready to upload to YouTube Studio. More accurate than YouTube's built-in auto-captions across 57 languages.
The Premiere Pro caption plugin
Need captions generated automatically?
The tools above work on subtitle files you already have. CaptionX generates accurate, timed captions from your video directly inside Adobe Premiere Pro — no exports, no uploads, no re-syncing.