Drop video here or click to upload
Supports MP4, WebM, MOV | Then upload SRT/VTT subtitles
Video is processed entirely in your browser. Nothing is uploaded to any server.
No library loading required. Start processing immediately.
Choose font size, colors, and position to match your needs.
Works with the most common subtitle formats.
Add subtitles to video online free with FreeToolBox — burn SRT or VTT subtitle files directly into your video as hardcoded captions using FFmpeg.wasm, all in your browser. Hardcoded subtitles are embedded permanently into video frames, ensuring they appear on any device or platform — perfect for social media videos, accessible content, and foreign language videos. Upload your video and subtitle file, choose font style and size, and download the subtitled video.
All processing happens locally in your browser — your video and subtitle files never leave your device. No watermarks are added. Completely free, no account required.
Hardcoded subtitles are permanently burned into the video image — they can't be turned off. Softcoded subtitles are a separate track that players can show or hide. This tool creates hardcoded subtitles, ideal for social media where separate subtitle tracks aren't supported.
SRT (SubRip Text) and VTT (WebVTT) formats are supported. SRT is the most common subtitle format and can be created with any text editor.
Yes. Adjust font size, choose text color, and select subtitle position (bottom or top of frame) before export.
No. FFmpeg.wasm processes everything locally in your browser. Neither your video nor your subtitle file is sent to any external server.