Burn Subtitles to Video
Hardcode SRT subtitle tracks directly into video frames with custom styling. All processing runs privately in your browser without uploading video files.
MP4, WebM, MOV, MKV, AVI, FLV, 3GP · up to 1 GB
Tips
- Save your SRT file in UTF-8 encoding to prevent missing accented letters and non-Latin character corruption.
- Burned subtitles become permanent video pixels and cannot be toggled off or hidden during playback.
- The browser engine downloads once, stays cached locally, and functions completely offline on future visits.
How to use it
- 1 Select or drop your video file and matching SRT subtitle file into the workspace.
- 2 Adjust the subtitle font size, alignment, and vertical position on the preview.
- 3 Start the encoding process to burn the subtitles permanently into the video.
- 4 Save the completed video file directly to your local storage.
What you should know
Hardcoding subtitles embeds caption text directly onto the video frames as permanent pixels, eliminating playback inconsistencies across platforms. While soft subtitles rely on player support and separate tracks inside containers like MP4 or MKV, social media feeds, digital signage, and embedded players frequently strip or ignore external subtitle streams. Burning subtitles into the rasterized image guarantees that your typography, timing, and positioning remain identical regardless of the viewer's device or application. Because burning text modifies the visual stream, the video must undergo lossy re-encoding, where setting an optimal Constant Rate Factor balances text sharpness against compression artifacts.
This tool burns SRT subtitle files into your video entirely in your browser using client-side WebAssembly. You can adjust the subtitle font size, placement, and line presentation before rendering the final file. Since processing runs inside a single browser thread, encoding longer clips or high-definition 4K footage requires notable CPU time and may take longer than the video runtime. The rendering pipeline copies existing audio tracks losslessly while re-encoding the video stream. Note that burned subtitles cannot be removed, styled dynamically after export, or hidden by the end viewer once encoded.
Frequently asked questions
Can viewers turn off subtitles after they are burned in?
No, hardcoding draws the subtitle text directly onto the video frames as raw pixels, meaning viewers cannot disable or hide the captions.
Why does burning subtitles take longer than simple container conversions?
The browser must decode each video frame, render the subtitle text overlay onto it, and re-encode the entire video stream using a single-threaded WebAssembly engine.
Are my video and subtitle files uploaded to any external server?
No, all processing occurs locally inside your browser tab without transmitting your media or transcript files over the internet.
Guides
Articles and format references related to this tool.
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