How to Add Subtitles to a Video (Free, No Upload)
Updated 2026-07-15
To add subtitles to a video, open the Add Subtitles tool, drop in the video, then either upload an SRT/VTT caption file or auto-generate captions with on-device AI. Style them, preview exactly how they'll look, and export an MP4 with the captions burned in — all in your browser, with nothing uploaded.
Burned-in vs. soft subtitles — which do you need?
- Burned-in (hardcoded) captions are drawn into the pixels. They can't be turned off, they survive every platform and messenger, and they're the standard for TikTok/Reels/Shorts where most viewers watch muted. This is what this tool produces.
- Soft subtitles are a separate text track (an SRT file) the player overlays. YouTube supports uploading them alongside the video — for that, you don't need burning at all; edit and download the SRT with the Subtitle Editor and upload it in YouTube Studio.
Rule of thumb: short-form social video → burn them in; YouTube long-form → upload an SRT as well. Doing both is common: burn stylish captions for the Shorts cut, keep a clean SRT for the main upload.
Two ways to get the captions
Upload an SRT or VTT. If you already have a caption file — exported from an editor, a transcription service, or the Subtitle Editor — drop it in and every cue appears on a timeline, editable before burning.
Auto-generate on your device (AI). On a desktop browser, the tool runs OpenAI's open-source Whisper model locally: the model weights download once (~145 MB) and the audio itself never leaves the tab — unlike cloud caption services, which upload your footage. Pick the spoken language, let it transcribe, then fix any word inline. On phones, AI generation is unavailable, but the SRT path works everywhere.
Styling captions that actually get read
The style presets map to the three looks you see everywhere:
- Clean bar — white text on a soft dark bar; the professional/interview look.
- Bold outline — heavy white type with a black stroke, the "Shorts style" built for small screens and muted autoplay.
- Minimal — plain white with a shadow, for when the footage should dominate.
Font size is set as a percentage of the video's height, so the same setting looks right on landscape and vertical clips. Keep captions to two lines, and if the clip is destined for TikTok/Reels, position them high enough to clear the platform's caption band — the Vertical Video Converter shows those safe zones.
Step by step
- Open the Add Subtitles to Video tool and drop in your video.
- Upload an SRT/VTT — or click auto-generate (desktop) and pick the language.
- Skim the cue list; click any cue to fix wording. You can also download the corrected SRT for reuse.
- Pick a style preset, size and position; the live preview shows the exact final look.
- Export MP4, watch the progress, preview the result, save. No watermark, ever.
Privacy
Caption SaaS tools upload your video twice — once to transcribe, once to render. Here both steps happen in the tab: Whisper runs on your GPU via WebGPU, and the burn-in uses your browser's own encoder. Your footage never leaves your machine.