Why do teams still hard-burn captions when every player claims to support sidecar subtitles?
Autoplay feeds default to mute, older WebViews ignore external tracks, and enterprise IM previews often ship video-only blobs. Hard-burning rasterizes text into every frame so promos, compliance lines, and pricing survive forwarding chains. People search burn subtitles into mp4 online, hardcode srt to video without premiere, tiktok captions burned in, corporate wechat video subtitles, and ffmpeg wasm subtitles because installs and codec drift are the real bottlenecks. Whole-second timelines reduce accidental drift, but rap-style VO still needs human listening checks. Rare glyphs may fall back when font subsets miss codepoints, so scan product names before launch. Burning never redacts sensitive UI—blur or crop first. Ai2Done frames Add Subtitles as pick text vs file mode, validate timecodes, burn locally, mute-preview on a phone, then ship versioned MP4s plus archived sidecars.
How to ship a hard-burn MP4 that survives mute autoplay reviews
- Open Add Subtitles in Chrome or Edge, upload the master clip, read the size and duration caps, and confirm SRT files are UTF-8 with cues aligned to the final edit timeline.
- Use text mode with HH:MM:SS rows for hooks and offers, or switch to subtitle-file mode after QC; tune font size, contrast, and bottom safe margins so faces stay visible in 9:16.
- Export, then mute-autoplay the first ten seconds on cellular data inside the destination app; log a version string in the filename and keep lossless masters plus sidecars in governed storage.