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Automatically run WebPageTest against code change?

Get set up with one of our API subscriptions to automate your website performance testing and unlock features such as:

  • Set and enforce budgets for any metric of WebPageTest
  • Complete control over WebPageTest test settings (authentication, custom metrics, scripting, etc)
  • Automatically create comments on new pull requests with key metrics, waterfall and more.

Check out one of our API subscriptions and unlock the full potential of WebPageTest!

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Collaborate with your team easily using WebPageTest API?

The WebPageTest Slack bot lets you run tests against WebPageTest from within Slack. Once the tests are complete, a copy of the waterfall and a link to the full results will be posted in your Slack channel, helping you to easily troubleshoot and diagnose performance issues directly from your Slack development channels.

Get set up with one of our API subscriptions and unlock the full potential of WebPageTest!

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Hitting the test limit?

Set up with WebPageTest API to increase your test run limits and automate your web performing test. With WebPageTest API, you can run tests, and easily diagnose and troubleshoot performance issues from within your favorite dev environment. Seamlessly add automated testing to your continuous delivery workflow.

WebPageTest API subscriptions start from as low as $15 to run 1,000 monthly tests.

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Don't want to wait? Have your test prioritized!

Did you know that our API test is running at the highest priority over the manual test? Set up with WebPageTest API to get faster access with your test results. and automate your web performing test. With WebPageTest API, you can run tests, and easily diagnose and troubleshoot performance issues from within your favorite dev environment. Seamlessly add automated testing to your continuous delivery workflow.

Check out one of our API subscriptions and unlock the full potential of WebPageTest!

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You can check out your site’s Core Web Vitals metrics in minutes via using WebPageTest—it’s free.

Your site’s discoverability is determined by many SEO factors — including Core Web Vitals. With WebPageTest Core Web Vitals test, you can get:

  • In-depth metrics + Waterfalls
  • Exportable, powerful visualizations
  • CrUX + Lighthouse data
  • Developer-first API & integrations

And more!

Check out one of our API subscriptions and unlock the full potential of WebPageTest!

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O'Reilly has published "Using WebPageTest"

Written by some long-time users of WebPageTest, it begins with the basics of running tests and interpreting the results, before moving on to using the API and installing your own private instance.

The full list of contents is available from O'Reilly

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With the official WebPageTest GitHub Action, you can automatically run tests against WebPageTest on code changes, set and enforce budgets on any of the metrics WebPageTest can surface (spoiler alert: there's a lot), and automatically generate comments on new pull requests with key metrics, waterfalls and more.

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Manning has published "HTTP/2 in Action" by Barry Pollard

HTTP/2 in Action teaches you everything you need to know to use HTTP/2 effectively and how to optimize web performance for your site. Using tools like WebPageTest, this practical guide explores real world examples allowing you to get most out of this recent performance upgrade to the web.

The full list of contents is available from Manning and WebPageTest users get 40% off with the discount code webpagetest40%.

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ImageOptim You can make your images download faster, without sacrificing quality. Use a lossless optimizer such as ImageOptim or FileOptimizer.

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Scott Jehl's video lecture course Lightning-Fast Web Performance is now free and available on WebPageTest.org.

Enjoy and share with anyone looking for a rounded intro to fast, resilient delivery.

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MozJPEG is a modern JPEG compressor that encodes JPEG images with higher quality and smaller file sizes than a typical encoder. Read introduction to MozJPEG at Performance Calendar.

MozJPEG is meant to be compiled as a drop-in replacement of the libjpeg library. It's also built into ImageOptim and you can try it via a web interface.

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Integrate WebPageTest with your existing CI/CD tooling?

WebPageTest API Wrapper is a NPM package that wraps WebPageTest API for NodeJS as a module and a command-line tool. It provides some syntactic sugar over the raw API, enabling easier integration into your existing workflows, including built in polling for results, pingback support and more.

Check out one of our API subscriptions and unlock the full potential of WebPageTest!

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Nik Molnar recorded a Pluralsight course called WebPageTest Deep Dive which covers everything from executing simple tests and analyzing their results, to scripting, custom metrics and hosting your own private instance of WebPageTest. Not a Pluralsight subscriber? You can watch any of Nik's courses with the free ten day trial.

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With pngquant you can convert large, transparent 24-bit PNG files to a format that is 4 times smaller, and supports alpha transparency in all browsers.

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Patrick Meenan published his "WebPageTest Power Users" Velocity conference talk to YouTube (Part 1 and Part 2).

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A Book Apart has published "Responsible JavaScript" by Jeremy Wagner

JavaScript plays a powerful role in creating rich interactive experiences. But its power comes at a cost: longer load times, sluggish pages, and inaccessible content. The more we rely on client-side rendering, the more likely we are to exclude visitors with older devices, slower connections, or those who have disabled JavaScript altogether.

If we want people to fully experience the sites we have worked so hard to craft, then we must be judicious in our use of JavaScript. In thoughtful detail, Jeremy Wagner shows how JavaScript can be used to progressively enhance server-side functionality, while improving speed and access for more visitors. By centering user needs every step of the way—from toolchains to metrics to testing—we can all contribute to a more inclusive, accessible, and resilient web.

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Do you care about Real User Performance Data as well? Answer this survey and stand a chance to with WebPageTest t-shirts, Amazon giftcards and more!

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Take the 2022 SRE survey

Catchpoint is conducting a SRE survey and is calling on Site Reliability Engineers, DevOps evangelists and anyone invested in reliability. Please take our 2022 SRE survey and contribute to improving SRE practices and making the internet a better place.

With every survey taken, Catchpoint will donate $5 to the International Red Cross and Blameless will donate $5 to Girls Who Code.

Click here to take the survey.

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SyntheticGuide Catchpoint has published the "The Guide to Synthetic Monitoring"

This guide is an ongoing series dedicated to answering common questions from practitioners about synthetic monitoring.

Learn how to monitor web performance, transactions, DNS, CDN, and more.

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HTTPS has a lot of opportunity for tuning on the server side that can significantly impact the speed at which your content is delivered.

Ilya Grigorik collected the current best practices on istlsfastyet.com and has published his excellent Velocity Conference talk on the topic to YouTube.

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If you instrument your pages to measure the user experience points that you care about most you will get MUCH more actionable results and can measure the performance from your actual users in the field.

More details are available here.

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WebPageTest's Visual Studio Code Extension, lets you run tests against WebPageTest from within VS Code. When the tests are complete, you'll see a summary of your performance metrics, the waterfall, a screenshot and a link to the full results displayed right in VS Code, bringing performance testing closer to the point where you're actually writing code, helping you spot performance issues much earlier in the development process.

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Google has published a bunch of best practices for web development including information on delivering a fast user experience.