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A Safe Stylish Alternative for Custom Website CSS

16 May 2026 · by JustZix Team

If you are looking for a safe Stylish alternative for custom website styles, you have probably read something about the extension's history and want a tool you can trust. This guide covers that history factually, looks fairly at Stylus, and explains where JustZix fits — so you can choose with clear information rather than rumor.

What Stylish did, and the history

Stylish was a popular extension for applying custom CSS — "userstyles" — to websites. It let you install themes and tweaks from a community catalog and made restyling pages easy for non-developers.

Here is the part to state carefully. Some years ago, Stylish drew widely reported criticism over collecting users' browsing data after a change of ownership. That reporting is part of the public record. We are not going to exaggerate it or imply anything beyond what was reported — and tools and ownership can change over time. The practical takeaway for a reader today is simple: when an extension can see every page you visit, it is reasonable to care about its data practices and to prefer transparent ones.

What to look for in a safe alternative

Rather than judging by reputation alone, judge by properties you can check:

• Transparency about data. Does it have a clear privacy policy? Does it collect browsing data?
• Open source or auditable behavior. Can the code or the network traffic be inspected?
• Minimal permissions. Broad permissions are sometimes necessary, but the tool should explain why.
• No telemetry by default, or at least clearly disclosed and optional.

Stylus — the open-source CSS-focused option

The most common recommendation, and a fair one, is Stylus. Important: Stylus is a separate, independent, open-source project — not the same thing as Stylish despite the similar name. It is CSS-focused, has a capable editor, supports the UserCSS format, and because it is open source its behavior can be audited.

Stylus is a strong pick when: you only need CSS, want a focused styling tool, and value an open-source codebase. It does exactly one job and does it well.

JustZix — CSS, JavaScript and dev tools, no telemetry

JustZix is a free Chrome extension (also Edge, Brave, Opera, Vivaldi) that injects custom CSS and JavaScript into pages via rules matched on URL patterns. It requires no account and runs no telemetry.

Compared with a CSS-only tool, JustZix gives you more reach when you need it:

• CSS and JS in the same rule — restyle and add behavior together.
• Folders, groups and rules for organizing styles across many sites.
• In-tab developer windows — a CSS pane, JS pane, JS Console REPL and a six-tab Output Console — so you can tweak a style live and see the result instantly.
• Optional sync via a locally generated key; the backend stores only a SHA-256 hash of that key, never your styles in plaintext tied to an identity.
• Rule-bundle sharing through short links with a 1–48h TTL.

On the data question — the thing this whole article is about — JustZix's position is that it has no telemetry. Sync is opt-in and key-based. You can read the full feature breakdown on the features page.

A practical example

Say a site uses a font you find hard to read. A scoped rule in JustZix for https://news.example.com/* with this CSS fixes it:

/* More readable body text */
article, .post-body, p {
  font-family: Georgia, 'Times New Roman', serif !important;
  font-size: 19px !important;
  line-height: 1.7 !important;
}

The same job works in Stylus. The difference shows up when you also want behavior — for example, auto-expanding "read more" sections — which needs JavaScript.

CSS-only or CSS plus JS?

This is the real decision:

• If you only ever restyle — dark themes, fonts, hiding elements — a CSS-only tool like Stylus is a clean fit.
• If you sometimes need behavior too — clicking things, rearranging content, small fixes — a CSS+JS tool like JustZix saves you juggling two extensions.

Both can be "safe." Safety is about data practices and transparency, not about whether the tool also runs JavaScript.

How to choose

Bottom line

The Stylish history is a fair reason to choose carefully — but the lesson is to pick a tool with transparent data practices, not to be afraid of custom CSS in general. Stylus and JustZix are both reasonable, honest choices; the right one depends on whether you also need JavaScript.

See also

• How to add custom CSS to any website
• Best Tampermonkey alternatives

If a no-telemetry, no-account tool that handles both CSS and JS sounds right, JustZix is free — visit the download page to install it.