Per-site CSS and JavaScript. Write a snippet once, pick the sites it belongs to.
Users
6
+5 in 30 days
Rating
5.0 / 5
+5.00 in 30 days
Ratings
1
+1 in 30 days
Store rank
#232K
#194K among extensions
Version
1.0.0
updated 8 Sep 2026
Users
monthly, 1 months
Latest, 16 Oct 2026:6 usersMove the mouse over the chart for any month
Ratings count
monthly, 1 months
Latest, 16 Oct 2026:1 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Boosts
Every site has one thing you would change. A docs page with a column too narrow to read. A sidebar you have never once looked at. A header that follows you down the page. A font two sizes too small on the one dashboard you stare at all day.
You notice them every single day, and you fix them never, because fixing them means opening DevTools, and DevTools forgets the moment you reload.
Boosts remembers. Write a snippet of CSS or JavaScript, point it at the sites it belongs to, and it is applied every time you visit them.
WHAT YOU GET
- CSS and JavaScript per site, with a real editor: line numbers, auto-indent, bracket completion and syntax highlighting for both languages.
- CSS applies live. Save and every open tab updates, with no reload.
- Friendly site patterns. Type github.com and get every subdomain. Type localhost:3000 and the port is dropped for you, because match patterns already cover every port.
- Everything autosaves.
- Ordering you control, because two boosts on one site are resolved by their order.
- One switch to pause every boost at once.
PRIVACY
Boosts makes no network requests of any kind. No account, no server, no telemetry, no analytics. Everything you write stays in your browser's local storage. The full source is at https://github.com/o-ba/boosts under the GPL-2.0.
Imported files always arrive switched off, and you are shown what a file wants, which sites and whether it runs JavaScript, before anything is stored.