Trusted by 10,000+ creatorsAuto caption generator
No account required. Start in seconds.
Caption any video, automatically
AutoSubtitles is a free browser-based auto caption generator. It transcribes your video audio with AI, lets you edit the wording and timing, and exports either a captioned video or a subtitle file. Free to start with no signup; no install needed.
Why creators choose AutoSubtitles
Total control over every caption
Customize every detail: fonts (upload your own with Pro), colors, outline, shadow, background, casing, spacing, alignment, position, and animation. Or start from 28 presets.
Renders in your browser, fast
No waiting to upload your video to a server and no render queue. It stays on your device and captions render right in your browser, so you get your captioned video in seconds.
Viral animated captions
Word-by-word animations and karaoke highlighting in bold, readable styles built for TikTok, Reels, and Shorts.
Export however you need
Download a captioned video with burned-in subtitles on any plan. With Pro, also export SRT, VTT, and TXT files to use anywhere.
Translate into 30+ languages
Translate your captions into 30+ languages with AI while keeping the timing intact.
Free to use, private
Use it free; a paid plan unlocks more. Your video file never leaves your device; only the audio is sent for transcription, then deleted.
Features
AI transcription built for video
Turn speech into caption text in seconds, even with accents and conversational pacing.
Editable captions
Correct wording, timing, and line breaks before you export. The AI gets you close, you keep control.
Caption styling
Apply ready-made styles or customize fonts, colors, outlines, and position.
Fast, browser-side rendering
Exports render in your browser, not on a server, so there is no upload and no render queue. Nothing to install.
Made for YouTube creators, short‑form editors, and educators.
YouTube creators
Caption long-form videos automatically, then export hardcoded captions or a subtitle file.
Short-form editors
Add captions to TikTok, Reels, and Shorts without a heavyweight timeline tool.
Educators
Caption lessons quickly to improve accessibility without manual transcription.
How it works
- Step 1
Upload your video
Drag and drop an MP4, MOV, or WebM file. Your video stays on your device; only the audio is sent for transcription.
- Step 2
Auto-generate captions
AI transcribes the audio in seconds, in any of 100+ languages.
- Step 3
Review and edit
Fix any words, adjust timing, and split or merge lines so captions read naturally.
- Step 4
Export
Download a subtitle file or export a video with captions burned in.
Free vs Pro
Start free, upgrade only if you need more.
| Capability | Free | Pro |
|---|---|---|
| Automatic caption generation | Yes | Yes |
| Editable text and timing | Yes | Yes |
| Export captioned video | Yes | Yes |
| Animations and word highlights | Yes | Yes |
| No watermark | No | Yes |
| HD and 4K export | No | Yes |
| AI translation | No | Yes |
| Custom fonts | No | Yes |
| SRT, VTT and TXT download | No | Yes |
| Saved style presets | No | Yes |
No account required. Start in seconds.
Frequently asked questions
- How do I automatically add captions to a video?
Upload your video to AutoSubtitles, let the AI generate captions, review the text, and export a captioned video or subtitle file. The whole process takes a few clicks, and no signup is required to start.
- Is the auto caption generator free?
Yes. You can generate, edit, style, and export captions for free with no signup, including every animated style. Free exports have a small watermark. Pro removes it and adds HD and 4K export, translation, and more.
- How accurate are the automatic captions?
The AI produces an accurate first draft from your audio, then you can correct any words and fine-tune the timing before exporting, so the final captions are as accurate as you need.
- What video formats are supported?
You can upload MP4, MOV, WebM, and most common video formats. Captioned videos export as MP4, and subtitle files export as SRT, VTT, or TXT.
- Does my video get uploaded to a server?
No. AutoSubtitles renders in your browser, so your video is never uploaded. Only the audio is sent, for transcription. Browser-side rendering also makes exports fast, with no server render queue.