Add Subtitles to a Video

Three ways to get the words

Every subtitled video starts with timed text: what is said, when it starts and when it ends. The editor accepts that text from three places, and you can mix them, for example by letting AI write a draft and then typing a few lines it missed.

AI subtitles

The speech is transcribed and timed for you, in the language spoken or translated into one of 21 languages. Best when nobody has written the subtitles yet.

An SRT or VTT file

Import a subtitle file from a translator, a client, YouTube Studio or another tool. Best when the text already exists and only needs to reach the picture.

Typing

Pause where a line should start, press Enter and type. Best for short clips, a handful of on-screen notes, or videos with little speech.

Whichever you choose, the lines land in the same list and timeline, so the editing and styling steps afterwards are identical.

How to add subtitles to a video

1. Open the editor on this page and choose a video file: MP4, MOV, M4V, WebM or MKV.
2. Leave "Write the subtitles automatically with AI" on to have them generated, or switch it off and import an SRT or VTT file, or add lines yourself.
3. Play the video and read along. Click any line to fix a word, or drag its edges on the timeline to change when it appears.
4. Open Style and pick a preset, then adjust the font, size, colours and position until it looks right on the preview.
5. Click Render video, check the summary and start it, wait while your browser encodes the new copy, then click Download video. Use Export SRT or Export VTT too if you want a subtitle file as well.

The preview is drawn by the same code that renders the final video, so line breaks and positions in the download match what you saw.

What happens when AI writes them

When AI subtitles are on, your browser pulls the audio out of the video, compresses it and sends only that audio for transcription; the picture stays on your computer. The speech is recognised with Whisper, the spoken language is detected automatically, and you can ask for the subtitles in another language instead. The result comes back as short one-line captions that start on the first spoken word of each phrase, which suits phones and sound-off viewing better than long sentence-sized blocks. AI subtitles need a Google sign-in because they use credits; see what free covers for the free allowance.

AI is a draft, not a finished product. Names, brands, numbers and words that sound alike are where errors cluster, and music under speech makes everything harder. Budget a watch-through before you publish; fixing auto-generated subtitles has a review order that catches most problems quickly.

Subtitles in the file or in the picture?

There are two kinds of subtitled video, and the choice decides how you publish.

• Soft subtitles live in a separate file or track. Viewers can switch them off, and platforms such as YouTube can index them, but messaging apps, most social feeds and many embedded players ignore them.
• Burned-in subtitles are part of the picture. They show everywhere the video plays, look exactly as you designed them, and can't be turned off.

The editor gives you both from one session: the rendered MP4 has the subtitles burned in, and the SRT and VTT exports are soft subtitles for platforms that accept files. If you only ever need the file, the AI subtitle generator is the shorter route. The trade-offs are covered in more depth on burn subtitles into a video.

Making them readable

A subtitle that is accurate but unreadable fails just as badly as a wrong one. A few habits make most videos work:

• Keep lines short. One line at a time reads faster on a phone than a two-line block.
• Use contrast. White text with a dark outline or a semi-transparent box stays legible over bright skies and dark rooms alike.
• Mind the edges. Apps draw buttons and captions over the bottom and right of vertical videos; the safe-area guide shows where text is at risk.
• Give each line time. Very short lines flash past; the editor warns when a line is faster than people can comfortably read.

For style specifics, subtitle styles walks through the eight presets and the best fonts for subtitles compares the bundled typefaces.

Where the work happens

Rendering a subtitled video means decoding every frame, drawing the text on it and encoding it again. Here that happens on your own computer through your browser's built-in video encoder, so there is no upload of the video, no queue and no watermark. Speed depends on your hardware and the length and resolution of the video; a short 1080p clip is usually quick, while a long 4K file takes a while and needs free disk space. The tab has to stay open until the download is ready.

Rendering needs a recent desktop browser: Chrome or Edge 94 or later, Safari 16.4 or later, or Firefox 130 or later. On older browsers you can still edit and export SRT or VTT, then render elsewhere.

A worked example

When to use a different page

If your video is going to one platform, its page covers the layout rules: YouTube, TikTok or Instagram Reels. If you already have a subtitle file and just need it in the picture, start at SRT to MP4. To get the speech as text without subtitles at all, video to text is the right tool, and for a subtitle file in another language there is translated subtitles.

About the subtitle editor on this page

Opens

MP4, MOV, M4V, WebM, MKV videos your browser can decode

Subtitles from

AI (from the speech, optionally translated into one of 21 languages), an SRT or VTT file, or typing them in

You download

An MP4 with the subtitles drawn into the picture at the original resolution and frame rate, plus SRT and VTT files

Cost

Editing, styling, rendering and SRT/VTT export are free, with no account and no watermark. AI subtitles cost 1 credit per minute (5-credit minimum per video); signing in with Google gives 100 free credits and accounts get 10 free credits a day

Privacy

The video never leaves your device and is rendered in your browser. Only for AI subtitles is the audio sent, over HTTPS, and it is deleted within 30 minutes of delivery

Rendering needs

Chrome or Edge 94+, Safari 16.4+, or Firefox 130+ on a computer. Editing and SRT/VTT export work in any current browser