MEPX
Chapter 8 of 10All chapters
  1. 1How a page arrives
  2. 2HTML
  3. 3CSS
  4. 4Layout
  5. 5JavaScript in the browser
  6. 6Accessibility
  7. 7Performance
  8. 8State and storage
  9. 9Tools and frameworks
  10. 10Deploying

Chapter 8 of 10

State and storage

Remembering things in the browser.

The options

localStorage keeps small values on one device until cleared. sessionStorage lasts for the tab. Cookies go to the server with every request, which is why sessions use them.

  • Never store anything sensitive in the browser; the user and their extensions can read it.
  • Assume storage can fail or be empty and handle that path.

URLs are state too

Putting filters and page numbers in the URL makes a view shareable, bookmarkable and survivable across reloads. It is the cheapest state management there is.