Dev Tools Tabs Explained — Plus Tips & Tricks

In this episode of Syntax, Scott and Wes talk about dev tools tabs, what each tab does and how you can use them.

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Show Notes

3:50 - Network

See all requests, filter by type or name
Used to understand all requests coming or going
Turn off caching
View timing
See the true GZIP size
Slow down network speed
See time for page load
Copy as fetch or CURL
View request, response, and headers
See CORS issues
See which requests have happened
See if an asset is cached (both in dev tools, also Cloudflare)
See blocked requests because of extensions
Tip: You can see the network info from the console in Firefox

22:03 - Memory

See what is taking up memory
- Strings
- DOM nodes
- Objects
- Actual .js

26:44 - Performance

Click record and use the site
Flame chart useful for finding slow functions and debugging janky animations
Get FPS in coordination with flame chart
Save performance recording data to be able to share for debugging
You can also upload saved data to debug without using the site

30:48 - Console

Interfaces with the JS runtime
Shows errors, warnings, and logs
Tip: Negate noisy warnings/errors that clutter your console with -
Tip: Use $0 to select current element
- $1 for second last
- $r for current React element
Tip: Use $$ to shortcut Query SelectorAll and Array.from
Tip: Use $ to shortcut Query Selector

40:28 - Storage / Application

Working with LocalStorage, Cookies, Index DB, and Session Storage

44:56 - Audit / Lighthouse (Chrome and Firefox)

Run lighthouse to check for performance, accessibility, and UI stuff
Not the silver bullet audit that many people think it is
- Colors are sometimes like “Really?!”
Can be helpful regardless

50:28 - DOM Tab