Burn Subtitles into Video: Hardcode SRT to MP4
Drop a video and its SRT, VTT or ASS file, pick a caption style, and download an MP4 with the subtitles burned in. Free, with no sign-up.
Drop a video and its subtitle file
or click to browse
Supported: MP4, MOV, M4V, WEBM, MKV, SRT, VTT, ASS, SSA, LRC
Drop a video and its subtitle file
Glad it worked. SubtitleKit is free and runs on tips. Still free, still runs on tips.
How to burn subtitles into a video
Drop your video and its subtitle file
Drag both onto the page at once, or one after the other, or click to choose them.
Pick a style
Choose Classic, Box, Yellow or Word highlight, then a size and a position. The preview shows the result on your video as you change it.
Burn the subtitles
Press Burn subtitles and keep the tab open while the progress bar runs.
Download the MP4
Press Download MP4. The subtitles are now part of the picture.
Burn subtitles into a video so they show everywhere
Some players, apps and social sites ignore a separate subtitle file. This tool draws your subtitles into the picture itself and writes a new MP4, so the words show on every screen the video plays on, with nothing to switch on.
How burning subtitles into a video works
Your browser reads the video and the subtitle file first, so the preview shows the subtitles on the picture before anything is made. When you press Burn subtitles, it decodes the video frame by frame, draws the subtitle that is on screen at that moment in the style you picked, and encodes the result as a new H.264 MP4. The sound is copied as it is when it is already AAC, and converted to AAC otherwise. The preview and the finished video use the same drawing code, so what you see is what you get. No subtitles yet? Make them first with Generate Subtitles.
MP4, MOV, WebM or MKV and SRT, VTT or ASS in, MP4 out
The video can be an MP4, MOV, M4V, WebM or MKV. The subtitles can be SRT, VTT or ASS, or another timed subtitle format the site reads, such as SSA, SBV or LRC. The finished file is an MP4 with H.264 video and AAC sound, the same size and frame rate as your video up to 1080p. From an ASS file the text and the karaoke timing are used; its fonts, colours and positions are not, and the style is the one you pick on the page.
Your video stays on your device
The video and the subtitle file stay on your device. Your browser reads them, draws the subtitles and writes the MP4, and sends them nowhere, which is also why a long video starts right away instead of waiting for an upload. An internet connection is needed to load the page and its fonts.
Limits
The finished video is at most 1080p; a larger video is scaled down to 1080p. On phones and on devices with 4 GB of memory or less it is at most 720p, because a larger picture can run the browser out of memory. There is no length limit, but the device needs free storage of about the size of the video while it works, and older Safari versions take videos of up to about 250 MB. The whole picture is encoded again, so the time depends on your device, and a browser that cannot encode H.264 video cannot burn subtitles.
Frequently Asked Questions
How do I burn subtitles into a video?
Drop the video and its subtitle file on this page, pick a style, press Burn subtitles, then download the MP4. The subtitles become part of the picture, so they show in every player.
How do I add an SRT file to an MP4 permanently?
Drop the MP4 and the SRT file here and press Burn subtitles. The new MP4 carries the text in its picture, so it cannot be switched off or lost when the video is uploaded or shared.
What is the difference between burned-in and soft subtitles?
Soft subtitles are a separate track or file that the viewer can switch on and off, and some players and sites drop them. Burned-in subtitles, also called hardcoded or open captions, are drawn into the picture, so everyone sees them and nobody can turn them off.
Can I make word-by-word captions?
Yes, when the subtitle file has a time for each word. ASS karaoke, WebVTT with inline timestamps and Enhanced LRC carry them; pick Word highlight and each word lights up as it is spoken. A plain SRT has one time per line, so its subtitles show a line at a time.
Which subtitle and video formats work?
Subtitles in SRT, VTT, ASS and the other timed formats the site reads, and video in MP4, MOV, M4V, WebM or MKV. A video in another container, such as AVI, needs converting to MP4 first. The result is always an MP4.
Is my video uploaded?
No. The video and the subtitle file stay on your device, and the MP4 is made in your browser.
How long does it take, and is there a size limit?
Every frame is encoded again on your device, so a recent computer is fastest and a phone is slower; the progress bar shows the time left. There is no length limit, except about 250 MB in older Safari versions. The finished video is at most 1080p, and at most 720p on phones and devices with 4 GB of memory or less, and the device needs free storage of about the size of the video.
My video has no subtitles yet
Make them first with Generate Subtitles, which writes an SRT from the speech in your video on your device, then come back and burn it in.
Tips for readable subtitles
Check the timing first. Scrub the preview to a few lines. If the subtitles run early or late, fix them with Shift Subtitles before you burn them in.
Pick Box when the video is bright or busy behind the text; the dark box keeps every word readable.
For a vertical video, Middle keeps the subtitles clear of the app buttons at the bottom of the screen.
