v1.3.5 Chrome · Manifest V3 · Free

CSS edits that
survive the reload.

PersistCSS™ puts a real CSS editor in Chrome's side panel, built for developers, designers, and QA testers. Prototype changes, debug layouts, and save per-site CSS that comes back every time you visit.

  • Saved per site
  • Reapplies after every reload
  • Local-only, no account

Built for the CSS work DevTools forgets

Everything you would try in DevTools, except it is still there tomorrow.

Real editor, not a textarea

  • Ace Editor with CSS syntax highlighting
  • Nord dark theme
  • Lint feedback catches typos before you apply

Per-site CSS that persists

  • Styles save against a domain
  • Re-apply on every page load
  • Load early to reduce unstyled flashes

Element picker

  • Point at anything on the page
  • Get the shortest unique selector, ready in the editor
  • Works even when class names are hashed

Live preview

  • Valid CSS applies as you type
  • Turn it off to apply when you are ready
  • A hint flags edits that are out of sync

Saved Sites manager

  • Search every domain you have customized
  • Open, edit, enable, disable, or delete
  • In-row confirm prevents accidental deletes

Aggressive overrides

  • One toggle beats stubborn stylesheets
  • Adds !important to your declarations
  • Uses the browser's own CSS parser

Syncs across your tabs

  • Edits reach every open tab of a site
  • Not just the tab in front of you
  • Side-by-side windows stay in step

Accessible by design

  • Nord theme meets WCAG AA contrast
  • Visible keyboard focus indicators
  • Panel structure built for screen readers

A better place to experiment with CSS

Test responsive tweaks, visual fixes, layout ideas, and accessibility improvements directly on the page.

Three steps, then it's just there

No accounts, no config files, no build step.

  1. 1

    Open the side panel

    Click the PersistCSS icon in your toolbar. The panel opens beside the page, so your CSS and the site you're styling stay visible at the same time.

  2. 2

    Write your CSS

    Type it, or use the element picker to grab a selector. The editor lints as you go and tells you when something won't parse.

  3. 3

    Apply, and forget about it

    Click Apply CSS. It's saved against that domain and re-applied on every future visit until you disable or delete it.

Your CSS never leaves your browser

PersistCSS has no account, no cloud, and nothing to sync, by design. Your saved CSS stays in Chrome's local storage on your machine, so there is no server it could leak from and nothing to sign up for.

  • No data collection. PersistCSS never collects, profiles, sells, or transmits your browsing data or CSS.
  • Local storage only. Everything PersistCSS saves stays on this machine, and uninstalling removes it all.
  • No analytics or telemetry. The extension never calls home and loads nothing from third parties.

Install PersistCSS

A quick add from the Chrome Web Store. No account, no setup.

  1. Open the Chrome Web Store listing.
  2. Click Add to Chrome, then confirm the permissions prompt.
  3. Pin PersistCSS to your toolbar from the puzzle-piece menu.
  4. Click the icon on any site to open the side panel and start writing CSS.
  5. Want somewhere to practice? Open the demo page (opens in a new tab), built to be restyled.

Requires
Chrome 114 or later on desktop, for side panel support.

Costs
Nothing. Every feature is free and ungated, with no Pro tier. Donations are optional and help development continue.

Add to Chrome

PersistCSS is a one‑person labor of love

PersistCSS exists because I wanted a better way to work with CSS on live sites. If it’s helping you explore, test, and build faster too, a coffee helps me keep improving it.

Buy me a coffee

Something not working? Report a problem.
No account needed, and an email address is optional.