About imgOptimizer – image optimization online

imgOptimizer is a free service for compressing and converting images online. Reduce the file size of PNG, JPEG, WebP, GIF, AVIF, BMP, TIFF and SVG with no visible quality loss – right in your browser or via our REST API.

58.4% average savings
100 597 optimized images
Optimize an image now Read the API documentation

What is imgOptimizer?

imgOptimizer is a tool for image compression and format conversion that runs entirely in the cloud. The service is built for web developers, content creators, e-commerce merchants and anyone who wants faster page loads, better Core Web Vitals and lower bandwidth costs – without installing anything locally. Drag and drop your image on the start page, or call our REST API directly from your application.

Why optimize images?

Images often account for more than half of the data traffic on a modern web page. An unoptimized PNG or JPEG can easily be 5–10 times larger than it needs to be. This affects:

  • Page load time – slower pages lose visitors.
  • Google ranking – Core Web Vitals (LCP, CLS, INP) factor into search results.
  • Mobile experience – users on 4G/5G pay in both time and data.
  • Server costs – smaller files = lower CDN and bandwidth bills.
  • The environment – less transfer, less energy use.

How imgOptimizer works

We run every image through a chain of industry-leading open source tools – jpegoptim, mozjpeg, optipng, pngquant, oxipng, cwebp, avifenc, gifsicle – and keep the smallest file that still holds up in quality. Metadata (EXIF, GPS, camera info) is stripped automatically. You can choose format, max size and compression level, or just upload and let the defaults do the work.

Two ways to use the service

The start page – drag and drop

Visit the imgOptimizer start page and drop an image into the box. You get back an optimized version instantly, without an account and at no cost. Perfect for quick one-off optimizations of images for blogs, social media, product photos or email.

To the start page

REST API – for developers

Our REST API lets you integrate image optimization directly into your application, CMS or build pipeline. Send a POST to /api/v1/optimize with your image and optional parameters – get back the optimized file. Code examples are available in cURL, Python, JavaScript and PHP.

To the API docs

Format support

imgOptimizer handles all common image formats on the web, including modern formats like WebP and AVIF that produce 25–50% smaller files than the equivalent JPEG/PNG.

  • JPEG – photos, product images. Lossless re-encoding plus optional lossy optimization.
  • PNG – graphics with transparency. Multi-encoder lossless + optional quantization.
  • WebP – modern replacement for JPEG/PNG. Lossless, near-lossless and lossy.
  • AVIF – next-generation format, best compression but a bit slower.
  • GIF – animated images. Color reduction and frame optimization.
  • SVG – vector graphics. XML cleanup and precision reduction.
  • BMP / TIFF – best converted to a modern format for large savings.

A full list of input and output formats is available in the API documentation.

Privacy and security

Uploaded images are deleted right after download or within 10 minutes at the latest. We store no personal data, EXIF data or GPS coordinates – all metadata is stripped during optimization. Public uploads are protected with an HMAC token and an origin check to prevent abuse.

Frequently asked questions

Is imgOptimizer free?

Yes. The web interface is free to use without an account. API access requires a key – get in touch and we'll set one up for you.

How large files can I upload?

Up to 20 MB per image via the web interface.

Does the image lose quality?

With the default setting (quality=10) we run aggressive lossy optimization but only accept the result if it stays above a quality threshold. If you choose quality=1 we run lossless only re-encoding – no visible difference, but smaller savings.

Can I convert between formats?

Yes. Choose the desired output format (JPG, PNG, WebP, GIF or AVIF) either in the upload form or via the output_format parameter in the API.

Can I resize the image?

Yes. Specify a max size as WIDTHxHEIGHT (e.g. 1000x1000). The image is scaled to fit inside the box while keeping the aspect ratio and is never scaled up.

Get started

Need to optimize a single image? Go to the start page and drop it in. Building a service where image optimization should happen automatically? Read the API documentation and get going in a few minutes.

Optimize an image See the API docs