When ever I do a front-end review for webpages I start compiling a new checklist of things that I need to take into account for the review.
Now I tried to collect some of the most important questions to check for and release them publically.

Lately Google published their Progressive Web App Checklist which made me think about which are important thinks to look after before you publish a website or shop.

The provided checklist can help you with your existing webpages and for future projects. It's also great to use it as a pre-launch checklist.

For the future I hope to extend this list with the help of the community and automate as much checks as possible to compile a comprehensive report. If you got some ideas please feel free to contribute.

If you do reviews of websites and/or find any issue with the provided list, please contribute over at GitHub.

If you want to know more about about what is going wrong with your website and how this affects your users hire me for a review.

View the repository Hire me for a review

👆I've published a checklist for front-end related website reviews.https://t.co/0P8SA1zbzF

– Hans Christian Reinl (@drublic) December 6, 2016

Update: 29. January 2017

I just found this article on Smashing Magazine talking about a Front-end Performance Checklist: Front-End Performance Checklist 2017 (PDF, Apple Pages).

Frontend Checklist for Websites

Performance

General

• HTTP/2 is being used
• CDN is used for static files
• CDN is used for content pages
• Cookie-Less Domain is used for static files
• DNS prefetching is used
• <link rel="preload" as="script"> (CSS, JS and fonts)
• <link rel="dns-prefetch"> (for Domain, which provides static resources, eg.: Images, and Tracking Tools)

Resources

• JavaScript combined in one file

• JavaScript minified

• JavaScript is compressed

• No JavaScript inline

• CSS combined in one file

• CSS minified

• CSS is compressed

• CSS: No usage of @import

• No CSS inline

• HTML minified

• Static files are compressed with gzip

• Static files are pre-compressed on the server

• HTML is compressed with gzip

• Usage of correct image image formats

• Usage of responsive images

• Images are optimized (ImageOptim…)

• Image are cached in the browser

• SVG files are minized

• SVG files are used where possible

• Only fonts that are used are loaded

• Browser cache is used

• ETags is not used

• Expires, cache-control and max-age headers for static resources is set to 1 year

• Asychronous loading of non-critical content

• Tracking scripts loaded asynchronously

Measurements

Usually I measure the main pages of a project here.

• Count of all files
• Size of all files combined
• Download time of the page
• Google Page Speed analyses (Desktop, Mobile and Mobile UX; x of 100)

Rendering Performance

• Image sizes are specified on the website
• CSS is loaded in the header
• Scripts are loaded in the footer
• Scripts are loaded with defer-attribute
• Scripts are loaded in the header after styles are loaded
• Scrolling is possible with 60fps
• No usage of document.write

Device performance

• CPU usage
• Memory usage
• GPU usage

Cross-Browser

• Website is loading on all current desktop browsers (Safari, Firefox, Chrome, IE11, EDGE)
• Website is loading on all current mobile browser (Chrome for Android, iOS Safari)
• For Shops: Checkout is usable on all devices and browser necessary
• Viewport Meta Tag is used correctly
• Usage of correct input types

SEO

• Pages can be indexed

• Mobile version of website is available

• HTTPS is used on all pages

• Sitemap is available

• Structured-Data is used where possible

• Headlines used

• Headlines in correct order

• Meta descriptions used

• Meta keywords used

• Meta title is filled correctly

• Keywords used in headlines

• Images use the alt-attribute

• Links use a title-attribute

• Links in navigation do not use title-attribute

• No Duplicate Content

• Usage of absolute URLs

• Internal links point to HTTPS version of page

• Redirects are done with 301

• No 404-errors

• No 500-errors

• Canonical Tags are used if applicable

• Ratio Code:Content is around 25% for shop pages and 50% for content pages

Accessibility

• Color Contrast is good (WCAG 2.0)
• WAI-ARIA roles are used
• Usage of accessible elements like nav, footer, aside
• URLs are accessible
• Keyboard accessibility is available
• Correct input types are used

Security

• HTTPS is used on all pages
• There is no mixed content on the pages
• external plugins and trackings get loaded via HTTPS
• Robots.txt is in use
• Cross-Site-Scripting is not possible
• HSTS Header is set

More

• Strict usage of domain with or without www
• Correct language set in HTML tag
• Charset is set
• HTML is valid
• 404-page is available
• A special print style sheet is in place

Server

• Correct language set by the server
• Correct content types set by the server