How do I set the start and end of the clip?

Pass start and end inside the params object. Each can be a timestamp string like "00:01:30.500" or a number of seconds like 90.5. The clip covers the half-open range [start, end), so the frame at end is not included.

Is the cut frame-accurate?

Yes. Fotovid re-encodes the selected range with x264 rather than copying to the nearest keyframe, so the clip begins and ends exactly where you asked. The tradeoff is a re-encode, which is the same reason this is painful to run yourself on serverless.

What format is the output?

The result is always an MP4 re-encoded with x264, returned as a fotovid-hosted URL in the response's url field along with the clip's duration.

How long is the result URL available?

Each response includes an expires_at timestamp. Treat the hosted URL as temporary and download the clip to store your own copy wherever you serve files from.

What does a trim cost?

Trimming is a usage-credit operation costing one credit per call. Credits are $1 for 100, and every account starts with free credits, so you can build and test before paying anything.

Can I use this instead of ffmpeg on Vercel or Lambda?

That's the point. Fotovid is the drop-in ffmpeg microservice for serverless — you make one HTTPS call instead of bundling ffmpeg, so there are no binaries, cold-start penalties, or memory limits to work around.

Video operation

Trim video to a frame-accurate clip, no ffmpeg to bundle.

Trim video to a clip that ends on the exact frame — Fotovid handles the keyframes so the boundaries stay clean. The drop-in ffmpeg microservice hands you a hosted MP4 URL.

Get your API key — free Read the docs →

curl -X POST https://api.fotovid.co/v1/video/trim \
  -H "Authorization: Bearer p6_YOUR_KEY_ID:YOUR_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "source_url": "https://cdn.yoursite.com/recording.mp4",
    "params": {
      "start": "00:00:05",
      "end": "00:00:20"
    }
  }'

Trimming video on serverless is harder than it looks

Cutting a clip sounds like one ffmpeg command, but running that command on Vercel, Lambda, or Workers means shipping a 70MB+ static binary, fighting cold starts and memory limits, and streaming the input in and the output somewhere it can live. Frame-accurate cuts force a re-encode, which pushes CPU and execution time past what most serverless functions allow. You end up maintaining infrastructure that has nothing to do with your product.

ffmpeg binaries blow past serverless bundle-size and memory limits
Frame-accurate trimming requires a re-encode — slow, CPU-heavy work functions time out on
You still have to handle downloading the input and hosting the resulting clip
Reach for this endpoint when you need clean highlight clips, social cuts, or short previews without owning a media pipeline

Request parameters

POST /v1/video/trim

Field	Type	Default	Description
source_url*	string (URL)	—	HTTPS URL of the source video
params.start*	string \| number	—	"HH:MM:SS(.mmm)" or seconds (e.g. 5.5)
params.end*	string \| number	—	Must be greater than start; truncated at EOF

How it works

Your first call in three steps

1
Get a free API key
Sign up and create a key from the dashboard. You authenticate by sending an Authorization: Bearer p6_<key_id>:<secret> header. Every new account starts with free usage credits, and $1 buys 100 credits — a trim costs one credit per call.
2
Call POST /v1/video/trim
Send a request to https://api.fotovid.co/v1/video/trim with a JSON body containing source_url (the HTTPS URL of your input video) and a params object holding start and end. Both accept either an HH:MM:SS.mmm timestamp or a plain number of seconds; the cut is frame-accurate over the half-open [start, end) range and re-encoded to MP4 with x264.
3
Use the returned clip URL
The response is flat JSON with id, type, a fotovid-hosted url for the trimmed MP4, an expires_at, and the clip duration. Download the file and store your own copy so you control where it lives — then serve it, attach it, or pass it to the next step in your workflow.

Frequently asked questions

Keep exploring

Serverless ffmpeg — all guides Trim audio API Video thumbnail API Run ffmpeg on Supabase Run ffmpeg on AWS Lambda Pricing

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