About ImageGuide

ImageGuide helps you choose image formats, reduce file sizes and fix slow-loading images. The guides include code examples, export settings and tools you can use on your own files. They are free to read without an account.

What you will find here

• 100+ guides: formats, compression, responsive images, Core Web Vitals, image SEO, and delivery.
• Free image tools: hosted conversion for supported format pairs, plus local compression, analysis, comparison, PDF, and video tools.
• Reference sections: recommended dimensions per platform, per-industry workflows, and per-platform guides for Shopify, WordPress, Wix, Squarespace, and Webflow.
• Markdown and structured data: llms.txt, an AI info page, markdown versions of every guide, and schema markup.

Who publishes it

ImageGuide is published by Sirv, an image CDN and dynamic imaging company based in Oxford, United Kingdom. Sirv handles image delivery, resizing, zoom, 360 spins, and AI-powered image editing for e-commerce sites. Sirv also provides the hosted format converter on this site. The guides cover Sirv and other tools, including open-source options.

The Benchmark Lab publishes the source image, encoder settings and file sizes behind the homepage comparison. That test uses one image. Try the settings on your own files before choosing a format.

How we write these guides

The guides are written and maintained by the Sirv team. We use AI tools to draft and update parts of them, because the reference material changes often: browser support, encoder versions, platform limits and pricing all move. A person at Sirv checks every guide before it is published, and we correct pages when the facts change rather than rewriting them to look new.

Sirv publishes this site and sells an image CDN, so we say so on every guide that mentions Sirv. The guides also cover competing services and open-source tools. Numbers in the charts come from the Benchmark Lab, which publishes the source image, the encoder settings and the resulting file sizes. If you find an error, tell us and we will fix it.

How the site is built

The site is built with Astro. Sirv's CDN resizes images and selects a format for the browser. Below-the-fold images use lazy loading.