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Firefox-native · Actively maintained

The CSS inspector
Firefox has been missing.

PeekCSS is a Firefox-native CSS inspector. Hover any element to read its styles, pull full color palettes and fonts from a page, and export production-ready tokens — without ever opening DevTools.

No account needed to start. Pro unlocks palettes, exports & assets.

screenshot: sidebar inspector on a live page (hero.png)
500k+
CSS Peeper users with no Firefox option
4 tabs
Inspector · Overview · Typography · Settings
~103 kB
Total bundle — no bloat, no trackers
Why PeekCSS

Inspect any element without opening DevTools.

CSS Peeper is Chrome-only and has said no to Firefox for years. PeekCSS fills that gap — a native sidebar inspector that reads computed styles, extracts palettes and fonts, and exports production-ready tokens, all without the DevTools rabbit hole.

Inspector Free

Hover, click, read the CSS.

A pixel-accurate overlay follows your cursor. Click any element to load its full computed CSS into the sidebar — grouped and copyable.

  • Smart hover targeting. Empty containers resolve down to the nearest visible child, so you always land on what you meant.
  • Grouped properties. Typography, Colors, Spacing, Effects and Layout — with one-click copy for a value, a group, or everything.
  • Contrast built in. Every color pair shows its ratio with an AA / AAA pass-fail badge.
  • Your units. HEX / RGB / HSL and px / rem / pt, applied everywhere from Settings.
screenshot: inspector-tab.png

Overview Free account · Pro exports

The whole page's design, at a glance.

Pull every color and image off a page in one pass. See how each color is actually used, then export the palette in the format your codebase speaks.

  • Palette extraction. Up to 120 deduplicated colors, each tallied by text / background / border usage.
  • Export anywhere (Pro). CSS custom properties, SCSS variables, a JSON object, or a Tailwind colors config.
  • Image grid + download. Every <img> and CSS background image with thumbnails; grab one or download all as a ZIP (Pro).
  • Accessibility score. Estimated share of text passing AA/AAA, plus a list of failing pairs.
screenshot: overview-tab.png

Typography Free account · Pro pairing

Every font on the page, sorted.

See each font family, how often it's used, its weights and sizes, and the roles it plays — then get pairing suggestions without sending a single byte about the page anywhere.

  • Usage-ranked font list. Families sorted by element count, with distinct weights and sizes per family.
  • Role breakdown. Headings / Body / UI / Other chips, with a sort-by-role toggle.
  • Privacy-first pairing (Pro). Uses Google Fonts’ public catalog after you grant access. Detected fonts never leave your machine.
screenshot: typography-tab.png

Ultimate AI

Turn inspection into finished output.

The Ultimate tier adds AI on top of every Pro feature — naming, cleanup, and generation, with a generous monthly quota and per-action opt-in.

  • Semantic color naming. Get human-readable token names and a clean export, not just hex codes.
  • CSS cleanup on export. Redundant declarations collapsed, values normalized as you export.
  • Recreate this component. Generate clean markup + CSS from any inspected element.
  • Accessibility fixes. Concrete suggestions to push failing contrast pairs over the line.
screenshot: ai-features.png
Built for speed

Keyboard-first, always.

Q cycle tabs
W inspector on/off
E hover popup
N theme

Start inspecting in Firefox today.

Free forever for everyday use. Upgrade any time — one click, handled by Paddle.