CapStudio

Most AI caption tools make you upload your raw footage to their servers. CapStudio never does. It transcribes your short-form video and burns in styled, animated captions entirely in your browser: Whisper runs on WebGPU on your own machine, so your video never leaves your device, with no length limits and no per-export credits. How it works, all client-side: In-browser Whisper transcription (WebGPU, WASM fallback) with word-level timing, no API keys Caption styles: karaoke highlight, word pop, beast word-block, clean lower-third, and more Czech and Slavic languages that English-first tools get wrong Burned-in MP4 export rendered on your machine via WebCodecs For TikTok and Reels captions, YouTube Shorts, podcast clips, and faceless content. Free to start, no signup, no API keys. Works in Chrome and Edge at capstudio.xyz.