AI transcription with Whisper
Captionly runs OpenAI Whisper directly in your browser. 99+ languages, automatic detection, near-broadcast accuracy on clean audio.
"Hello, world!"
"Amazing video!"
"Subscribe now!"
"Watch this..."
Drop your clip and Captionly transcribes it with AI, applies a TikTok-ready caption style (Neon, Karaoke, Bounce, Pill, Rainbow…) and lets you download the burned-in MP4. 100% in your browser. No watermark. No signup.
TikTok rewards short, hooky videos with on-screen text. Captions tell the platform what your video is about, keep silent viewers watching to the end, and push your retention up — which is what the For You algorithm actually optimises for. Captionly is a free TikTok caption generator that does all of it in seconds, without uploading your video to anyone's server.
or click to browse your files
Supports MP4, MOV, AVI, WebM (max 500MB)
Built for the way TikTok creators actually edit — fast, mobile-first, no friction.
Captionly runs OpenAI Whisper directly in your browser. 99+ languages, automatic detection, near-broadcast accuracy on clean audio.
12 viral styles preset — Neon Pop, Karaoke, Bounce, Rainbow, Pill, Box Highlight and more. Pick one, tweak it, ship it.
We don't add a watermark, ask for an email, or cap how many videos you can caption. Free forever, no upsell.
Whisper misheard a slang word? Click the wrong word, type the right one, the timing stays intact. Edits propagate to the burned-in video automatically.
Download a finished MP4 with captions burned in, or grab the .srt file to drop into CapCut, Premiere, or TikTok's own caption uploader.
Your video never leaves your device. There's no server upload, no queue, no rate limit, and your raw footage stays private.
See how creators of every kind are using Captionly. Drag to browse, click to play.












Quick answers to the things people ask before captioning their next TikTok with Captionly.
Drop a clip, pick a style, ship the captioned MP4. The fastest way from raw footage to a captioned TikTok — built for creators who care about retention.