No processing of your file contents takes place on any server. You need no data-processing agreement with gottrix to handle confidential or business documents.
Hosted in GermanyGlobal Content Delivery
Origin servers at Hetzner in Germany, delivered worldwide through a content delivery network. Your file contents are never transmitted in the process - they never leave your device.
A reel for a platform without its own subtitle display, a training video that should always run with text, or a foreign-language recording with a permanently visible translation - this tool draws the lines of an SRT, WebVTT or ASS subtitle file directly into every frame of the video ("hardsub"), instead of producing a separate, toggleable track.
Drop exactly one video and exactly one subtitle file at the same time - the tool automatically recognizes which file plays which role (by file type/extension, not by drop order). The subtitle input format is auto-detected (SRT, WebVTT or ASS/SSA). Because burned-in text becomes part of the pixels, it can no longer be hidden or switched to another language afterwards - unlike a real subtitle track.
Everything runs locally in the browser with mediabunny (MPL-2.0, self-hosted, no third-party CDN) on the browser's native WebCodecs API. Your files are not uploaded. For a real, toggleable subtitle track, use the sibling SRT/VTT conversion tools instead.
Specifications
Specifications
Input formats
MP4, M4V, MOV, MKV, WEBM, SRT, VTT, ASS, SSA
Output format
MP4
Batch processing
Yes
Processing
Locally in your browser (WebCodecs)
File upload
None
In 3 steps
Drop one video and one subtitle file (SRT, VTT or ASS) together.
The tool automatically recognizes which file plays which role.
Download the video with burned-in subtitles.
Limitations: Needs exactly one video and exactly one subtitle file with at least one recognizable line. VTT position/alignment cues are ignored - every line appears bottom-centered. Full re-encode (every frame is redrawn), so it needs a hardware video encoder in your browser; without one, the tool says so honestly instead of producing unusable or crashing output. Each file ~600 MB limit individually (the browser tab's memory limit: without streaming support the file must fit in whole, with streaming it rises to about 1 GB).
FAQ
Are my files uploaded?
No. The whole burn-in happens locally in your browser.
Can I turn the subtitles off again later?
No. Burned-in text is part of the pixels and cannot be removed again - for that you would need a real, separate subtitle track instead of a hardsub.
Which subtitle formats are recognized?
SRT, WebVTT and ASS/SSA - the format is automatically detected from the content.
Why does the tool need a hardware video encoder?
Every frame is redrawn onto a canvas before it is encoded - on a pure software encoder that can crash the browser tab. Without a hardware encoder the tool honestly reports that instead of risking it.