How Amino Makes CSS Changes Persist on Any Website

Updated

Amino is a browser extension that lets you write CSS against any website and keeps those changes applied when you come back. It works by storing your rules in the extension and injecting them into the page each time that site loads, so persistence comes from the extension re-applying your CSS on every visit — not from editing the website itself. This suits anyone who wants a stable custom look for sites they use often, and it requires the extension to stay installed and enabled in the browser where you made the edits.

The persistence mechanism

The site's own files never change. Amino holds your CSS separately and re-injects it at page load, which is why the same overrides reappear on your next visit.

What happens on each page load

  1. You target a site. With the editor open on a page, you write CSS selectors that match elements on that site.
  2. Amino stores the rules. Your CSS is saved in the extension, associated with that site rather than with a single tab or session.
  3. The page reloads. When you revisit or refresh, the extension injects your stored CSS into the page.
  4. The browser renders your version. Because injected styles are applied after the site's own stylesheets, your rules win where specificity and order allow.

The expected result is that a change you made once is still there tomorrow, in a new tab, without you redoing it.

Why it survives without touching the source

  • No server access needed. You are not editing the site's codebase or asking its owners for anything.
  • No account on the target site required. The customization lives in your browser, not on their infrastructure.
  • Scope is per-site. Rules written for one domain are meant to apply there, so unrelated sites stay untouched.

Where persistence can break

Persistence is reliable in the normal case but has predictable failure points worth knowing before you invest time in a large stylesheet.

Situation What happens What to do
Extension disabled or removed Your CSS stops applying entirely Keep Amino enabled in the browser profile you use
Different browser or device Edits do not follow you automatically Recreate or re-import your rules where you need them
Site redesign changes class names Selectors no longer match, so styles silently stop working Update selectors to match the new markup
Site loads content dynamically Elements added after load may miss your rules Write selectors that still match, or target stable parent elements
Conflicting site styles win Your rule loses on specificity or order Increase specificity or use more precise selectors

The dynamic-content case is the one people underestimate. If a site renders parts of the page after the initial load, a rule that worked on first paint may not affect later-inserted elements.

Deciding whether this fits your use

Choose Amino-style persistent CSS when you want a repeatable personal theme for sites you visit regularly and you are comfortable writing or copying CSS selectors. Skip it when you need changes to apply for other people, when you cannot keep the extension installed, or when the site's markup changes so often that maintaining selectors becomes constant work.

A practical test: pick one site you use daily, write three or four rules, close the browser, reopen it, and confirm the rules are still applied. If they are, the persistence model is working for you; if not, check whether the extension is enabled and whether your selectors still match the current page.