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Free Online Image Tools

Compress, convert, resize, crop, and optimize images directly in your browser. Nothing uploads — your files stay on your device while every transformation runs locally using the Canvas API.

10 tools in this category · 100% free · No signup

All Image Tools

Why browser-based image processing matters

Most online image tools upload your files to a server, process them, and send them back. That's three risks: bandwidth waste, potential data leakage (especially for screenshots containing UI text or photos with metadata), and slower roundtrips. Modern browsers can compress, resize, crop, and convert images entirely in JavaScript using HTML5 Canvas — typically faster than uploading to a server, and verifiably private because the file never crosses the network.

Image optimization and Core Web Vitals

Largest Contentful Paint (LCP) — usually the hero image on a page — is one of Google's three Core Web Vitals ranking signals. Compressing images to under 100KB and serving them in WebP format can shave seconds off LCP. The Image Compressor and WebP Converter on this page handle exactly that. For automatic optimization in production, also configure your CDN (Cloudflare, BunnyCDN) or use Next.js's <Image> component, which serves WebP and resizes per device.

When to use each tool

Use Image Compressor when file size matters more than perfect fidelity (web hero, blog posts, social posts). Use Image Resizer when you need exact pixel dimensions (avatars, banners, thumbnails). Use PNG-to-JPG to drop transparency for smaller files when transparency isn't needed. Use WebP Converter when serving modern browsers — 25-35% smaller than equivalent JPG. Use Favicon Generator once per site to produce every favicon size browsers and iOS/Android expect.

Frequently asked questions

Is there a file size limit?
Browsers can typically handle files up to ~50MB for canvas-based operations. Beyond that, performance degrades. For very large images, use a desktop tool like ImageMagick or local Photoshop.
Why doesn't my PNG keep transparency after compression?
The Image Compressor outputs JPG (which has no alpha channel). Use the WebP Converter instead — WebP preserves transparency and is smaller.
Can I batch-process multiple images?
Not in these tools — each works on one image at a time. For batch needs, look at squoosh-cli (Google's CLI) or a build-time image plugin.