Free AI Subtitle Generator

Commercial use OK 380+ models No watermark No sign-up needed
Model:
+ GPT-5, Claude, Gemini
Drop a video — we transcribe it with Whisper, build an SRT or VTT subtitle file with word-level timing, and (optionally) burn the subtitles straight into the frame with a TikTok-ready style preset. 99 languages, auto-detect by default.

Drag a video here or click to upload

MP4, MOV, WebM, MKV up to 200MB — or MP3/WAV for audio-only transcription

Whisper supports 99 languages. Auto-detect works on 99% of clips.
SRT works in every player. VTT styles nicely in web video.
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Where subtitle generation earns its keep

TikTok / Reels / Shorts

85% of short-form watchers keep the sound off. Burn-in subtitles with the TikTok-tuned preset and your completion rate climbs.

YouTube closed captions

Pick SRT sidecar mode and upload the file to YouTube Studio. Better accuracy than YouTube auto-captions in most languages.

Corporate & e-learning

ADA / WCAG require captions on training videos. Generate once, spot-check, done.

Sidecar file vs. burn-in — which do I pick?

Sidecar SRT / VTT

Separate .srt or .vtt file. The viewer's player decides whether to show it. Works on YouTube, Vimeo, web HTML5 video, Netflix, VLC.

  • Cheaper — STT only, no re-encode.
  • Editable — you can fix typos in a text editor.
  • Toggleable — viewers turn subs on/off.

Burn-in (baked into video)

Subtitles are rasterized into each frame. Required for TikTok, Reels, Stories, and any platform that does not honor sidecar captions.

  • Guaranteed visible everywhere.
  • Style-locked to your chosen preset.
  • Permanent — keep the sidecar file for re-edits.

Why not Rev, Kapwing, or YouTube auto-captions?

Rev charges $1.50/minute for human captions ($90 for a 60-minute lecture). Kapwing charges $16/mo for unlimited auto-captions but puts a watermark on free exports. YouTube's auto-captions are Whisper-quality in English but noticeably worse in non-English. This tool uses the same Whisper model (large-v3) with no subscription, no watermark, and no per-minute fee — you pay tokens from the pool you already have.

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Want better results? Premium models (GPT-5, Claude, Gemini) deliver higher quality. View Plans

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Free AI Subtitle Generator. Use instantly with no sign up and no credit card. Powered by open-source AI models.

How to Use Free AI Subtitle Generator

1
Enter your input

Type text, upload a file, or describe what you want. No account needed.

2
Click generate

Our AI processes your request in seconds using the best open-source models.

3
Download & share

Download, copy, or share your result. Free for personal and commercial use.

Use this tool via API

Automate this tool from your own code. OpenAI-compatible REST endpoint, Bearer-token auth, no extra SDK required. Token costs match the web interface.

curl -X POST https://api.free.ai/v1/video/generate/ \
  -H "Authorization: Bearer sk-free-..." \
  -H "Content-Type: application/json" \
  -d '{"prompt": "A cat playing piano", "duration": 4}'

Free AI Subtitle Generator — FAQ

Upload a video and we transcribe the audio with Whisper, time-align each phrase, and return an SRT or VTT subtitle file — or burn the subtitles directly into the video with a style preset of your choice. Works in 99 languages with auto-detect.

Yes. Transcription is 12 tokens per second (400-token floor). A 60-second clip costs 720 tokens for a sidecar SRT; adding burn-in raises it to 1,920 tokens because we re-encode the video with a subtitle overlay. Both rates are inside the daily pool for signed-in users.

All 99 languages Whisper handles — English, Spanish, French, German, Italian, Portuguese, Mandarin, Japanese, Korean, Arabic, Hindi, Russian, Turkish, and 86 more. Auto-detect picks the right one automatically; you can override if the clip is multilingual.

SRT (SubRip — universal, works everywhere), VTT (WebVTT — HTML5 video native, supports styling hints). Plus burn-in mode, which re-renders the video with subtitles rasterized into the frame — post-to-TikTok ready.

Classic (white Arial, black outline, bottom centered), Cinema (bold box-style, high contrast), TikTok (yellow Impact, vertical-video optimized), and Clean (thin Helvetica, minimal outline). All four are styled via SubStation Alpha inside ffmpeg for correct anti-aliasing.

Sidecar when you still want users to toggle subtitles on/off (YouTube, web players, Netflix-style). Burn-in when the target platform does not honor sidecar captions (TikTok, Reels, Shorts in-feed, Instagram Stories). Burn-in is a one-way operation — keep the sidecar around if you might re-edit.

Whisper large-v3 reaches 95-98% word accuracy on clean English audio and 85-95% on non-English and noisy inputs. Always spot-check legal, medical, or public-facing captions. Accents and speaker overlap are the main causes of misrecognition.

Not directly — AI Subtitle Generator transcribes in the source language. For translated subs, export the SRT here, then upload it at /translate/subtitle/ and pick the target language. That preserves timing while swapping text.

Up to 200MB (usually 10–15 minutes at 1080p). Longer clips are fine in principle but may hit the 10-minute ffmpeg timeout on burn-in mode. Split long lectures into 5-minute chunks if you are burning in.

Kapwing charges $16/mo for unlimited captions; Rev charges $1.50/minute for human captions. AI Subtitle Generator is free inside your token pool and uses the same Whisper model that underpins many paid services — just without the subscription markup.

No. The upload is deleted as soon as subtitles are generated. The SRT/VTT and any burned-in MP4 live on our CDN for 24 hours (7 days for paid users) so you can download or share.

Yes. POST multipart to /v1/video/subtitle/ with `file`, `language`, `format`, optional `burn_in=true` and `font_style`. Pre-flight: GET /v1/video/subtitle-quote/?duration=SECS&burn_in=true. Full snippets at /api/.

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