Website Validation, Speed and Performance Optimization

A list of links with speed tests, tools and techniques to optimize page speed and the overall website performance. Managing page speed (the speed at which the website loads and reacts to user input) can drastically improve user experience (UX) and search engine optimization (SEO).

Speed

• Google PageSpeed Insights
  Analyzes the content of a web page, then generates suggestions to make that page faster.

• GTmetrix
  Gives insights on how well the site loads and provides actionable recommendations on how to optimize it.

• Pingdom Website Speed Test
  Enter a URL to test the page load time, analyze it, and find bottlenecks.

• KeyCDN Website Speed Test
  A page speed test that includes a waterfall breakdown and the website preview.

• Varvy SEO tool
  See how well a page follows the Google guidelines.

Validation

• W3C Markup Validation Service (HTML Validator)
  Checks the markup (HTML, XHTML, …) of Web documents.

• W3C CSS Validation Service (CSS Validator)
  Checks Cascading Style Sheets (CSS) and (X)HTML documents with style sheets.

• W3C Feed Validation Service (Feed Validator)
  Checks the syntax of syndicated feeds (Atom or RSS feeds).

• PowerMapper
  Checks any website for broken links, spelling errors, browser compatibility, accessibility, web standards validation and search engine issues.

• IONOS Website Checker
  Reviews the four most important aspects for your website’s online success: website presentation, search engine visibility, website security, website’s performance.

Test Tools

• Google Mobile-Friendly Test
  Tests how easily a visitor can use your page on a mobile device.

• Find Broken Links, Redirects and Site Crawl Tool
  Check All the Links on a Website

• Broken Link Checker
  Scans webpages for dead hyperlinks.

• W3C Link Checker
  Checks your web pages for broken links.

Other Tools

• CSS Sprites Generator #1

• CSS Sprites Generator #2

• Base 64 Image Encoder
  Create data streams for embedding images.

• TinyJPG
  Compress JPEG images intelligently.

• HTML Minifier
  A highly configurable, JavaScript-based HTML minifier.

• HTTP Header Check
  Online curl test to analyze HTTP Response Headers.

• Easy Counter
  Get a website analyzed and accurately described in terms of WHOIS record, traffic stats, metadata, safety, subdomains, server details and more.