To add captions to a video, upload the file, choose bottom or center and a size, then click Generate captions. The speech is transcribed and burned into a new MP4 you can download. It takes MP4, MOV, WEBM and MKV up to 10 minutes. For an SRT file instead, use Subtitle generator.
[ What it is ]
What is a video caption generator?
A video caption generator writes the speech in a clip onto the picture. You download a new MP4 with the captions burned in, so they play with the sound off and need no separate subtitle file.
A subtitle generator is a different tool: it returns an SRT file you load next to the video. This one returns the video itself, ready to post on Reels, TikTok or Shorts.
One run returns a new MP4 with timed captions on the picture.
[ What you get ]
An MP4 with captions burned onto the picture
What comes out:
- A preview. The captioned video plays on the page, so you can check where the words sit.
- The MP4 download. The same file with the captions burned in, ready to post without a subtitle track.
- One caption style. Choose bottom or center and a size (S, M or L) before you generate. Changing them later starts a new run.
For an SRT file instead, use Subtitle generator below.
[ How to use it ]
Video caption generator: three steps
Upload a video
Drop an MP4, WEBM, MOV or MKV, up to 10 minutes and 80 MB. A file that is not a video is rejected and does not use a run.
Choose position and size
Bottom or center, S, M or L. Then click Generate captions. Once the upload finishes, you can reload the page and pick the same run back up.
Download the MP4
Play the preview, then click Download MP4.
For a subtitle file instead of burned-in captions, use Subtitle generator below.
[ Limits ]
Free version limits
Your first run is free, no sign-up. Leave your email for one more, then create a free account and pay only for what you use.
[ Why marketers use it ]
Burned-in captions — your hook survives a muted feed
Most short video is watched with the sound off. Captions on the picture carry the first line, the offer and the call to action through a muted feed.
Captioning your own cut also shows where the hook lands on screen. If the first line wraps into three rows or covers the product, you see it before the ad goes out.
One captioned cut checks a single creative. Research is a different job: a competitor runs dozens of video ads, and the question is which hook they keep repeating. That is what Spytrend is for.
[ Go further with Spytrend ]
Every hook a competitor keeps paying for, in one place
Captioning one clip is a task. Seeing which hook a competitor repeats is a different job.
Spytrend is an ad intelligence platform for Facebook and TikTok advertising: a full five-year archive of ads, AI-classified into 33 business categories, with every advertiser assembled into a single card — all ads, pages, domains and countries in one place. On paid plans, any video ad in Spytrend can be transcribed in one click.
Who uses it
Media buyers and brand managers who need to read a hook on mute, and who would rather search a competitor’s whole run of ads than caption forty files by hand.
What you see in Spytrend
- Every creative a competitor runs. Compare the line you just burned in with the twenty ads around it.
- Run time. Launch date and days running, so a hook that has lasted for months stands out.
- Re-uploads. How many times the same creative was uploaded again as a new ad: somebody chose to pay for it twice.
How to start
Caption your clip here first. Create a free account: it opens the ad library, and paid plans add fresh ads and every filter. Search a competitor’s brand or domain and see which hooks they keep paying for.