Can I watermark both video and images with the same API?

Yes. Use POST /v1/video/watermark for video and POST /v1/image/watermark for images. Both take the same params — type, watermark_image_url, text, position, opacity, scale, and padding — so you can share one code path across media.

Can I overlay text instead of an image?

Yes. Set type to text and pass the text param. Use type image with watermark_image_url for a logo, or type combo to overlay both a logo image and text together.

How do I control where the watermark sits?

Use position to pick a corner or center (top-left, top-right, bottom-left, bottom-right, center), padding to inset it from the edge, scale (0–1, default 0.15) to size it relative to the frame, and opacity (0–1) to make it subtle or bold.

Where does my watermark image come from?

Pass watermark_image_url pointing at an https URL of your logo. Fotovid fetches it along with the source_url input — you don't upload files to us or stage anything on a serverless disk.

Is per-user tagging supported to deter leaks?

Yes — a common use case. Overlay per-user text (a username or ID) with type text, or combine a brand logo and unique text via type combo, so every exported clip is traceable back to the account that generated it.

Fotovid runs on usage credits: $1 = 100 credits and a watermark call is 1 credit. You start with a free key, so you can integrate and test before spending anything.

Watermark operation

Add a watermark to video or images — the API for logo and text overlays.

Overlay a logo image or text on any video or image with a single POST. Set position, opacity, and scale right in the request; a fotovid-hosted file comes back ready to serve.

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curl -X POST https://api.fotovid.co/v1/video/watermark \
  -H "Authorization: Bearer p6_YOUR_KEY_ID:YOUR_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "source_url": "https://cdn.yoursite.com/clip.mp4",
    "params": {
      "type": "image",
      "watermark_image_url": "https://cdn.yoursite.com/logo.png",
      "position": "bottom-right",
      "opacity": 0.7,
      "scale": 0.2
    }
  }'

Why watermarking on serverless is painful

Watermarking looks trivial until you try to run it inside a serverless function. ffmpeg's overlay filter needs the full binary plus your logo staged on a writable disk, then it decodes and re-encodes the whole file — which routinely blows past Lambda and Vercel execution limits and memory caps for anything longer than a short clip. You end up managing layer bundles, temp storage, and cold starts just to stamp a logo in a corner.

The ffmpeg binary and libraries balloon your deploy far past typical serverless size limits
Re-encoding a full-length video overflows function timeouts and memory
Overlaying an image means fetching, staging, and cleaning up files on ephemeral disk
Getting position, opacity, and scale pixel-perfect across resolutions is fiddly filter-graph work

Request parameters

POST /v1/video/watermark & /v1/image/watermark

Field	Type	Default	Description
source_url*	string (URL)	—	HTTPS URL of the source video or image
params.type	"image" \| "text" \| "combo"	"text"	Watermark kind
params.watermark_image_url	string (URL)	—	Logo image URL (required for image/combo)
params.text	string	—	Overlay text (required for text/combo)
params.position	string	"bottom-right"	top-left · top-right · bottom-left · bottom-right · center
params.opacity	number	1	0–1
params.scale	number	0.15	Watermark width relative to the source (0–1)

How it works

Your first call in three steps

1
Get a free API key
Sign up and create a key. You authenticate every request with an Authorization: Bearer p6_<key_id>:<secret> header. No card required to start — usage runs on credits ($1 = 100 credits, and a watermark is 1 credit).
2
POST your source and watermark params
Call POST /v1/video/watermark or POST /v1/image/watermark with the standard envelope: a source_url pointing at your input (an https URL), plus a params object. Set type to image, text, or combo, then pass watermark_image_url and/or text, along with position (top-left, top-right, bottom-left, bottom-right, or center), opacity (0–1), scale (0–1, default 0.15), and padding. Fotovid downloads the input, overlays the mark, and returns synchronously.
3
Store the returned result URL
The response is flat JSON with an id, type, and a fotovid-hosted url for the watermarked file (video responses also include duration). Download it and store your own copy — treat the hosted URL as a handoff, not permanent storage, since it expires.

Frequently asked questions

Keep exploring

Serverless ffmpeg — all guides Extract audio API Trim video API Run ffmpeg on Vercel Run ffmpeg on Supabase Pricing

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