Lightning-fast Image Resizing API

Resize and convert images on-the-fly. AVIF/WebP/JPEG/PNG. Smart quality.

curl -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://example.com/image.jpg",
    "w": 800,
    "h": 600,
    "fit": "cover",
    "fmt": "webp",
    "q": 75
  }' \
  https://api.imagick.tech/v1/images/resize -o result.webp

The problem

Slow pages from oversized images.
Bloated assets draining bandwidth.
Device and format fragmentation.
Ad-hoc scripts that are hard to maintain.

The solution

A single URL/API to resize, convert, compress, crop, and cache globally. Ship the smallest image that looks great—every time.

Live Demo

Upload or paste an image URL. Tune params. We generate a signed URL and show an estimated result client-side.

Image URL

Or upload

Drag & drop an image here, paste a URL above, or click to select

Width

Height

Lock Aspect Ratio

Fit

Quality (1–100)

Format

DPR

Background

Get API Key

Before

No image

Size: —

After (simulated)

Adjust params and Update Preview

Size: —

Preview and savings are estimations generated in the browser for demonstration purposes.

How it works

Client → Resize Endpoint → Transform → CDN cache → User
 |         |                  |            |\
 |         |                  |            └─> Global POPs
 |         |                  └─> AVIF/WebP/JPEG/PNG, crop, fit
 |         └─> POST /v1/images/resize or Signed GET /i/{signature}?...
 └─> Your app or website

URL params: url, w, h, fit, fmt, q, dpr, bg, fx, fy.
Headers: Authorization: Bearer API_KEY for POST. Signed GET requires HMAC SHA-256 signature and TTL.
Caching: CDN caches by full URL. Cache bust by changing params or version key.
Security: Signed URLs (HMAC-SHA256) with TTL and source-domain allowlist.

API usage

POST https://api.imagick.tech/v1/images/resize

curl -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com/img.jpg","w":1200,"h":800,"fit":"cover","fmt":"avif","q":60,"dpr":2}' \
  ${API_DOMAIN}/api/v1/images/resize -o out.avif

Errors: 400 (bad params), 401 (auth), 413 (too large), 415 (unsupported), 429 (rate limit), 5xx (server).

Signed GET https://api.imagick.tech/i/{signature}?...

GET ${API_DOMAIN}/i/{signature}?url=https%3A%2F%2Fexample.com%2Fimg.jpg&w=1200&h=800&fit=cover&fmt=webp&q=70&dpr=2&ttl=3600

Sign the query with HMAC SHA-256 using your server-side secret. Include ttl to bound validity.

Key features

On-the-fly Resize & Crop

cover / contain / fill. Focal cropping.

Format Conversion

AVIF/WebP/JPEG/PNG, fmt=auto.

Smart Quality & DPR

q and dpr parameters.

Lossless & Strip

Optional lossless, strip metadata.

Global CDN

High hit ratio, cache busting.

Audit & Analytics

Logs and usage dashboards.

Performance proof

Median transform time: ~28 ms at edge cache.
CDN cache hit ratio: 92–97% typical.
Byte savings: 55–85% vs. original JPEGs.

Item

Original

Optimized

Hero banner

980 KB, 2400×1200, JPEG

210 KB, 1200×600, AVIF

Product

420 KB, 1600×1600, PNG

96 KB, 800×800, WebP

Avatar

120 KB, 1024×1024, JPEG

28 KB, 256×256, WebP