FAQ

Kernline is a browser extension for Chrome, Edge, and Firefox. It inspects CSS, exports Tailwind and design tokens, lists assets, overlays mockups, copies an AI rebuild bundle, and captures components as HTML, React, or Vue. It runs only on the tab you open.

Your settings, saved overlays, cached licence state, and on Free a count of today's Copy for AI and Component captures. All of it is removed when you uninstall.

Open Kernline’s options page and use Revoke next to a granted domain. You can also remove the site under your browser’s extension permissions.

Pro is $36/year or $6/month, or $59 once for Lifetime Pro. Polar handles checkout. We don't know who you are unless you buy Pro or join the launch list.

Email support@kernline.dev from the address used at checkout and ask for Polar customer data to be removed. The same address deletes a launch-list signup.

Yes. Email support@kernline.dev within 14 days of payment for a full refund on any plan. Details are on the refunds page.

No. Everything happens in your browser, on the tab you opened.

Free includes the full inspector with unlimited CSS copy, single-element Tailwind, 3 Copy for AI and 3 Component captures a day, asset list with single downloads, and one saved overlay per site. Pro makes Copy for AI (trimmed HTML, styles, tokens, sizes, and hover or media states for AI coding tools) and Component capture (whole card, navbar, or section as HTML, React, or Vue with Tailwind) unlimited, and adds hover, focus, and responsive Tailwind variants, page-wide token export (CSS variables, Tailwind theme, JSON, or Copy for AI as tailwind.config or tokens file), bulk SVG clean and ZIP export, unlimited overlays with layers and breakpoints, and priority support.

Free gets 3 Copy for AI and 3 Component captures a day. Kernline counts them in the extension's own storage on your device and resets the count at your local midnight. Nothing is sent to us, and a copy only counts if it reached your clipboard.

One payment of $59 for every Pro feature, with no renewal. Your licence key never expires and includes future updates for as long as Kernline is sold. The terms explain what happens if Kernline ever stops.

Core inspection and copy work offline. Licence checks contact Polar when the extension opens or when you use Pro features. Cached licence status allows a grace period when offline.

Install Kernline, open it on the tab, pin the element, and click Copy for AI or use Component capture. Paste the text into Cursor or Claude. Step-by-step guide.

Yes. Kernline maps computed styles to Tailwind v3 or v4 on the element you pin. Pro adds variant classes and a full-page token scan. How to copy Tailwind.

Open Kernline on the page and use the Export tab. Pro scans the page for colours, fonts, spacing, and radii, then exports CSS variables, a Tailwind theme, or JSON. Design tokens guide.

Kernline uses activeTab at install and runs only when you open it on that tab. Cross-origin fetches need a per-domain grant you can revoke. How permissions work.

Kernline is available on Chrome. Edge and Firefox are in store review.

Alt + Shift + K opens Kernline. Alt + Shift + I is reserved by Chrome and Edge for their own feedback form, so Kernline does not use it.