Upscale an image

POSTupscalr.app/api/v1/upscale

Creates an upscale job. Send the file as multipart form data, or JSON with a publicly reachable image URL. Returns immediately with a queued job.

Request: multipart form data

Parameter	Type	Description
image	file, required	The image bytes. JPEG, PNG, WebP or AVIF, up to 10 MB.
target	string	Output size: 2k, 3k or 4k. Defaults to 2k.
format	string	Output format: png, jpeg, webp or avif. Defaults to png.

curl -X POST https://upscalr.app/api/v1/upscale \
  -H "Authorization: Bearer $UPSCALR_API_KEY" \
  -F image=@photo.png \
  -F target=4k

Request: JSON with a URL

If the image already lives at a public HTTPS URL, skip the upload and point us at it. The same size and format checks apply after we fetch it.

Parameter	Type	Description
image_url	string, required	Publicly reachable HTTPS URL of the image.
target	string	Output size: 2k–4k. Defaults to 2k.
format	string	Output format: png, jpeg, webp or avif. Defaults to png.
filename	string	Optional display name for the job.

curl -X POST https://upscalr.app/api/v1/upscale \
  -H "Authorization: Bearer $UPSCALR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"image_url": "https://example.com/photo.png", "target": "4k"}'

Output format

The engine itself always produces PNG. This app decodes and re-encodes it into whatever format you asked for before the result is stored. That re-encode also strips whatever metadata the engine left behind (EXIF, ICC, XMP), so GPS coordinates, camera serial numbers and capture timestamps from the source never reach the output. jpeg drops transparency; png, webp and avif keep it.

Parameter	Type	Description
png	lossless	Largest files. Keeps transparency.
jpeg	lossy	Smaller. No transparency.
webp	lossy	Small, and keeps transparency.
avif	lossy	Smallest. Slower to encode.

Scope

Requires the jobs:write scope. A key without it gets 403 forbidden. See API key setup.

Idempotency

Send an Idempotency-Key header (any unique string, a UUID is ideal) and retries become safe: repeating a request with the same key returns the original job with 200 instead of creating and charging for a second one. Use it on every submission that might be retried by your infrastructure.

Response

Response · 202 Accepted

{
  "id": "cmrw0iqm8000bdcs3um6ii7fa",
  "object": "job",
  "status": "queued",
  "target": "4k",
  "filename": "photo.png",
  "credits": 3,
  "source": {
    "bytes": 2148393,
    "content_type": "image/png"
  },
  "created_at": "2026-07-25T09:30:00Z"
}

Status	Meaning
200	Idempotent replay: the original job.
202	Job accepted.
400	Invalid request.
401	Missing or invalid API key.
402	Not enough credits.
413	Image too large.
415	Unsupported image format.
429	Rate limit exceeded.

Error bodies follow the shape described in Errors.

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