Video to SRT Converter

AudioSRT is a free browser-based video to SRT converter and subtitle editor. It accepts MP4, MOV, WebM, MKV and audio files, extracts the audio, and transcribes using OpenAI Whisper running locally — no upload, no account, no file size or duration limit. The built-in subtitle editor lets you fix timing, split lines, style subtitles, and export to SRT, VTT, Premiere Pro JSON, or burned MP4. Cloud AI with 100+ language support is available on Starter.

Video to SRT conversion means extracting the audio track from your video, transcribing it with AI, and generating a timestamped subtitle file that can be loaded into any video player or editor. AudioSRT handles the full pipeline in your browser — from video file to finished, editable SRT — without uploading anything to a server.

Why convert video to SRT?

An SRT file is the universal subtitle format. Every major platform — YouTube, Vimeo, Netflix — accepts SRT, and every professional editor — Premiere Pro, DaVinci Resolve, Final Cut Pro — can import it. Having a separate SRT file means you can update captions without re-exporting the video, translate to multiple languages, and share subtitle tracks independently of the media.

For video creators, accurate subtitles improve accessibility, boost watch time (captions increase average view duration by up to 40%), and are required by law in many contexts. Starting with an accurate SRT from your video is the right foundation for any captioning workflow.

Supported video formats

AudioSRT supports all common video formats without any conversion step:

• MP4 — the most common video format, used by cameras, phones, and screen recorders
• MOV — Apple's QuickTime format, common from Final Cut Pro exports and iPhone recordings
• WebM — open-source format used by web video and screen recorders
• MKV — container format common for high-quality video files
• AVI — older format still common in professional workflows
• M4V — Apple's video format, used by iTunes and Apple devices

There is no file size or duration limit on any format. A 2-hour film is processed the same way as a 2-minute clip.

How AudioSRT extracts audio from video in the browser

Most browser-based tools require you to upload your video to their servers for processing. AudioSRT uses FFmpeg.wasm — a WebAssembly port of FFmpeg — to extract the audio track directly in your browser. FFmpeg is the industry-standard open-source multimedia processing library used by YouTube, VLC, and virtually every professional media tool. The .wasm version runs entirely in your browser with no server interaction.

Once the audio is extracted (typically in seconds), it's handed to Whisper AI — also running locally via WebAssembly — for transcription. The result is a fully local pipeline: your video file is read, audio is extracted, AI runs, and an SRT is generated, all without a single byte leaving your device.

Step-by-step: video to SRT workflow

1. Open AudioSRT at audiosrt.com/tool. No account or installation required.
2. Drop your video file onto the upload area. AudioSRT detects the file type and begins audio extraction automatically.
3. Wait for transcription. The audio is processed in 30-second segments. A 10-minute video typically takes 2–4 minutes on a modern laptop. You can watch the transcript appear in real time.
4. Review the transcript. Click any word to correct it. The editor shows you the timestamp for every word.
5. Split long subtitle lines. Any subtitle longer than 42 characters per line should be split. Use the split control to divide it at the word you choose.
6. Style your subtitles (optional). Set font, size, color, shadow and position using the right-side controls. Changes appear in the live preview.
7. Export SRT. Click Export and choose SRT. Your file downloads immediately.

Browser AI vs cloud AI for video

The free browser tier (Whisper AI) is the right choice for single-speaker English video in reasonable audio conditions. It's private, unlimited, and requires no account. If your video has multiple speakers, background noise, heavy music, or is in a language other than English, Starter tier (Deepgram Nova-3) will produce significantly better results — and transcribes up to 30× faster, which matters for long videos.

Importing the SRT into YouTube

YouTube supports SRT file uploads directly: go to YouTube Studio, open your video, click Subtitles, then Add, select Upload file, and upload your SRT. YouTube will automatically match the timestamps. The process takes about 30 seconds and gives you a fully timed caption track you can continue editing inside YouTube Studio if needed.

Importing the SRT into Premiere Pro and DaVinci Resolve

In Premiere Pro: go to File → Import, select your SRT file. It will appear in the project panel and can be dragged to your timeline as a caption track. Alternatively, use AudioSRT's native Premiere Pro JSON export to get a fully editable caption track with your styling settings preserved.

In DaVinci Resolve: open the Edit timeline, go to File → Import Subtitles, and select your SRT file. The subtitles will appear as a subtitle track on your timeline. You can then edit the text and timing directly in Resolve's subtitle inspector.

Common mistakes with video subtitles

• Lines too long. Keep subtitle lines under 42 characters and 2 lines maximum. Longer lines are cropped on mobile screens.
• Timing mismatches. A subtitle that shows for 6 seconds covering 3 words looks wrong. Match display duration to reading speed.
• No speaker labels. For multi-speaker video, prefix each subtitle with the speaker's name in brackets: [Host], [Guest].
• Overlapping timestamps. SRT files with overlapping entries cause undefined behaviour in some players. AudioSRT's export validates all timestamps automatically.