Free Add Subtitles
Embed or burn subtitles into videos — 100% free in your browser.
Free How to use Add Subtitles
Video processing on DigitalConverter.online is powered by FFmpeg compiled to WebAssembly, which runs the encode, trim, transcode, and mux operations directly in your browser. Your footage is loaded into memory, processed frame by frame on your CPU or GPU where supported, and written back out as a new file you download locally. This approach keeps raw camera files, screen recordings, and personal clips off third-party servers, reducing exposure when you are editing material that includes faces, locations, or proprietary content. Processing speed depends on your device hardware, but the privacy trade-off favors keeping data on your machine.
What Add Subtitles does and when to use it
Add Subtitles embeds SRT or VTT captions into video files so viewers can follow dialogue on mute, meet accessibility expectations, and improve comprehension for multilingual audiences. Creators hard-burn subtitles for platforms that ignore sidecar files, while soft muxing preserves optional toggling where supported.
Accurate captions boost engagement on social feeds watched without sound and help compliance with accessibility guidelines for training and marketing videos. Burning text into pixels guarantees visibility on TVs and legacy players.
How this tool works
The tool parses subtitle files, aligns cues with the video timeline, and uses FFmpeg.wasm to burn text via filter graphs or mux subtitle streams into the output container. Font, size, and margin settings map to libass or drawtext configurations.
Rendering runs client-side; your footage and caption text are not uploaded. Long videos with many cues increase filter complexity and encode time.
Step-by-step instructions
Upload video and a matching subtitle file, verify timecodes align in preview, and choose burn-in or mux mode. Start processing and download the captioned video, then play on the target platform to confirm readability on mobile screens.
Tips and best practices
Keep lines under roughly 42 characters for mobile legibility and use high-contrast styles.
Review automatic transcripts manually before burning; proper nouns are often wrong.
Learn more: Compress Video for Email and Social Upload Limits
Add Subtitles FAQ
Answers to common questions about Add Subtitles.
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