How to add subtitles to a video (burn in an SRT or script)
Subtitles help people watching on mute, in noisy places or in a second language. This guide shows the quickest way to put them on a video without uploading it anywhere.
Burned-in subtitles vs a separate subtitle file
Burned-in (hard) subtitles are drawn into the picture, so they appear in every app and cannot be turned off. That is ideal for Shorts, Reels, TikTok and silent autoplay. A separate subtitle file (SRT or VTT) travels next to the video; viewers can switch it on or off, but the player or platform has to support it. Use burned-in subtitles when you need them to show everywhere; upload an .srt to YouTube or similar when you want switchable captions.
What an SRT file looks like
SRT is plain text. Each block has a number, a time range and the text: for example “1”, then “00:00:01,000 --> 00:00:03,500”, then the line of text, then a blank line. Times are hours:minutes:seconds,milliseconds. VTT is almost the same but uses a full stop in times. You can write one in any text editor, or keep the one a subtitle program gave you.
Add subtitles in three steps
Open Add Subtitles and choose your video. Then either upload an SRT/VTT file or paste a script. Check the timing in the subtitle list and on the timeline, drag blocks to move them, and edit text where needed. Finally pick the font, size, colours, outline and position and press Burn subtitles to download an MP4. Everything runs in your browser; the video is not uploaded.
You can also download the subtitles as an .srt file or save a project backup that keeps the styles, so you can come back later.
Make subtitles easy to read
Keep each line short — about 35–42 characters for Latin scripts, fewer for Chinese, Japanese and Korean — and at most two lines at once. Use a light colour with a dark outline or a background box so the text stays readable on bright and dark scenes. Keep subtitles inside the safe area, away from the edges where app buttons sit, and show each line for roughly one to six seconds depending on its length.
What automatic timing can and cannot do
If you paste a script without times, the tool splits it into short lines and spreads them by text length over the parts of the video that have sound. That gives a quick draft, but it is not speech recognition: it does not listen to the words, so lines can drift. Check the timeline and adjust the blocks, or use an exact SRT file when timing matters. Fonts for Chinese, Japanese, Korean, Thai, Vietnamese and English are included.
Tools used in this guide
Frequently asked questions
Can this create subtitles automatically from speech?
No. It burns in subtitles from an SRT/VTT file or a script you provide. Auto timing is only a rough draft based on text length and where the video has sound; it does not recognise speech.
Can viewers turn burned-in subtitles off?
No. They become part of the picture. If you want switchable captions, upload a separate .srt file to the platform.
Does it work for Chinese, Japanese, Korean, Thai and Vietnamese?
Yes. Fonts for these languages and English are included, so the text renders correctly in the burned-in video.
Is my video uploaded?
No. The video is processed in your browser and never leaves your device.