Four output shapes
Vertical, square, landscape or 720p from the same request, so one piece of content reaches a feed, a timeline and an embed.
Video API
Publishable short video from one API request
Send captions, a background and the shape you want, and get a finished MP4 back. Content that changes often becomes video without an editor, a timeline or an encoding pipeline to keep running.
Create a free accountRead the API docs
- Up to 60 seconds
- Vertical, square, landscape, 720p
- Refunds on failed work
- UK-operated infrastructure
Renders that ship themselves
vertical · 15s · captions timed
One request
Video is the format nobody has time to make
The content is usually already there: the headline, the number, the listing, the release note. What stops it becoming a clip is everything around it, which is an editor, an export, a naming convention and somebody remembering to do it.
Renderwolf takes the captions and the background and returns a finished MP4 in the shape you asked for. The clip is generated by the same system that already holds the data, at the moment the data changes.
POST /renderwolf/v1/video
Authorization: Bearer rw_live_...
{
"size": "vertical",
"duration": 15,
"colour": "#101820",
"captions": [
{ "text": "Renders that ship themselves" },
{ "text": "One API. One quota." }
]
}
200 video/mp4Capabilities
Enough control to publish, not enough to need training
The composition parameters that matter for short content, set per request.
Captions with your timing
Each caption carries when it appears and how long it holds, so the clip follows your script rather than a fixed cadence.
Your background
A flat colour, an image or a video behind the captions, with an optional watermark and a font size you control.
An audio bed
Supply audio with the request and it is mixed into the finished MP4, so the clip is publishable without a second pass.
No encoding pipeline
One HTTPS request instead of an ffmpeg toolchain, a render queue and a worker to keep alive between jobs.
Priced by output
Per second of finished video, with square and 720p cheaper than vertical and landscape. Failed work is refunded.
Use cases
Content that changes often enough to automate
Anywhere a person would otherwise open an editor to say something short.
Social posts from data
Turn a headline, a statistic or a listing into a publishable clip whenever the data changes.
News and update cards
Generate a short captioned clip per story, in the shape each platform wants.
Product and price updates
Announce a change with a clip built from the same record that changed.
Property and listing feeds
One clip per listing, generated on publication rather than edited by hand.
Status and metric summaries
Turn a weekly number into a short video for the channel that will actually watch it.
Scheduled content
Produce the week of posts from a queue, with captions timed the same way every time.
Recording an existing webpage instead?
This endpoint composes a clip from captions you supply. To record a page scrolling top to bottom, with the poster frame in the same response, there is a separate endpoint for that.
Website to video APIPricing
Priced per second of finished video
One credit per second for vertical or landscape output, 0.6 credits per second for square, and 0.5 credits per second at 720p. Start with 250 free credits each month and no card required. Failed work is refunded, cache hits cost nothing, and reaching a cap pauses rendering rather than billing overage.
Questions
Before you integrate
The details that decide whether this fits, without reading the whole reference first.
How long can a clip be?
Up to 60 seconds. Caption timing is yours to set, so the clip runs exactly as long as the content you send.
What aspect ratios can I get?
Vertical, square, landscape or 720p, so the same content can go to a vertical feed and a landscape embed without a second tool.
Can I use my own background?
Yes. Set a background colour, or supply a background image or video, add an optional watermark, and lay your captions over it.
Can I add audio?
Yes, an audio bed can be supplied with the request and is mixed into the finished MP4.
How is caption timing controlled?
Each caption carries its own timing, so you decide when a line appears and how long it holds rather than accepting a fixed cadence.
What does a clip cost?
One credit per second for vertical or landscape output, 0.6 credits per second for square, and 0.5 credits per second at 720p. Failed work is refunded and cache hits cost nothing.
What is the difference from the website preview API?
This composes a clip from captions and a background you supply. The website to video API records an existing webpage scrolling top to bottom. Different jobs, same key and quota.
Generate your first clip
Create an account, take a key and send a few captions. The first clip is inside your free credits.
250 free credits each month, with no card required, hard usage caps and refunds on failed work.