Free Tools

Performance Tools

Check response time, compression, caching, and other website performance signals.

10 tools in this category

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SSL Tools 3 DNS Tools 12 Domain Tools 12 Website Tools 19 Security Tools 10 Email Tools 8 Performance Tools 10 SEO Tools 12 API & Developer Testing Tools 17 Git & GitHub Tools 18 DevOps Tools 16 Linux & System Administration Tools 17 Database & SQL Tools 20 AWS & Cloud Tools 16 Kubernetes Tools 14 Programming Language Tools 23 Frontend / CSS Tools 20 Image / SVG Developer Tools 18 Security & Authentication Tools 14 File & Data Conversion Tools 20 Data / Number / Computer Science Tools 19 Software Version / Package Tools 9 Developer Documentation / Project Tools 11 Byte Array Tools 17 Text & Writing Tools 28 Finance & Loan Calculators 20 PDF Tools 16 Image Editing Tools 12

Run All Performance Tools Checks

GZIP Compression Checker

Check whether a website serves compressed (GZIP/Brotli) content.

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Brotli Compression Checker

Check whether a website serves Brotli-compressed content.

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HTTP Version Checker

Detect which HTTP protocol version a website serves (HTTP/1.1, HTTP/2, or HTTP/3).

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Cache Headers Checker

Analyze a website's caching headers - Cache-Control, Expires, ETag, Last-Modified, and Age...

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Keep-Alive Checker

Check whether a website supports persistent (Keep-Alive) connections.

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Page Size Checker

Check the HTML response size of a website's homepage.

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CDN Detection

Detect whether a website uses a common CDN provider.

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Performance Health Score

A combined performance overview - response time, compression, HTTP version, keep-alive, an...

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Render-Blocking Resources Checker

Check a page for render-blocking stylesheets and scripts in its <head> that could be slowi...

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Image Optimization Checker

Check a page's images for missing dimensions, missing lazy loading, and oversized file siz...

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Find the Easy Speed Wins First

A slow site is often missing server settings rather than needing new code. These tools check the response a real browser receives and point to the fixes that matter most. For an overview, start with the Performance Health Score, which combines several of the checks below.

Compression, Caching and Delivery

Text files shrink dramatically when compressed: the GZIP Checker and Brotli Checker show which compression a server supports. The Cache Headers Checker shows how long browsers may reuse a file, and CDN Detection tells you whether a content delivery network is in front of the site. The HTTP Version Checker confirms HTTP/2 or HTTP/3.

What the Page Itself Loads

Render-Blocking Resources Checker - scripts and styles that delay the first paint.
Image Optimization Checker - oversized images and missing dimensions.
Page Size Checker - HTML bloated by inline data.

Our guide to compression, caching and CDNs explains how to fix what these tools find.