CaptureKit - Full Page Screenshot & Annotate by Ali Raza Arshad

Take a full page screenshot of any website, mark it up in a complete editor, hide sensitive details with on-device AI, and save it your way — locally in Firefox by default. No account, no tracking, and nothing uploaded unless you turn on a feature that does.

CAPTURE, YOUR WAY
• Full page — scrolls and stitches the whole page into one seam-free image, including app-style pages (Jira, Notion, Gmail, Linear) that scroll inside an inner panel.
• Scrolling screenshot — scroll to where you want it to end, then click Done.
• Visible area, a drawn region, or a single element (hover, ↑/↓ to widen or narrow, click).
• Scrollable area — capture the full contents of an inner scroll box such as a chat thread or side panel.
• Timer — a short delay to catch hover menus and tooltips.

A COMPLETE EDITOR
• Pen, line, arrow, rectangle, ellipse, highlighter, text, callouts, emoji stamps, and numbered steps.
• Redact with blur, pixelate, or a solid bar — or paint with the object blur brush and the blur follows the object's outline. Spotlight a region.
• Crop with social-card presets, or let Smart crop trim blank margins in one click.
• Text with bold/italic, outline, background pill, superscript and subscript (m², H₂O, footnote¹).
• Multi-select, align and distribute, snap guides, lock and hide, style presets, and shape templates for watermarks and badges.
• Keys 1–9 switch tools; hold Space to pan around long captures. Full undo/redo.

SMART REDACT — ON-DEVICE (off by default)
Turn it on in Settings → AI features. One click finds emails, phone numbers, card numbers, IP addresses, IBANs, and faces in your screenshot and proposes a redaction over each. You accept or skip each one; nothing is hidden until you do. The text reader and face detector are bundled inside the add-on and run on your computer. Your screenshot is never uploaded. It reads English out of the box; in Settings you can add 19 more languages (German, French, Russian, Arabic, Chinese, Japanese, Korean…), each a one-click download.

CAPTION, IMPROVE AND ASK — WITH YOUR OWN API KEY (off by default)
Firefox has no built-in AI model, so these need a key you supply. In Settings, turn on AI features, then Cloud AI, choose Anthropic, OpenAI or Google Gemini, and paste your key. You then get Caption (a one-line description of a capture, for alt text or a filename), ✨ Improve (rewrites your annotation text shorter, clearer or more formal) and Ask… (ask questions about the capture). This is the only feature that sends a capture off your computer: Firefox asks permission before the first request, the editor names the provider before the first upload, your key stays on that computer, and the requests go straight to the provider on your own account — there is no CaptureKit server. Smart Redact never uses it.

AUTO-NUMBER
With the step tool, choose All buttons or All links and numbered markers are proposed over the page's buttons or links in reading order.

SAVE HOW YOU LIKE
• PNG, JPEG, multi-page PDF, or SVG (text and shapes stay editable in Inkscape or Illustrator).
• Editable PNGs — reopen a CaptureKit PNG later and every annotation comes back editable.
• Copy to clipboard, print, filename templates, and a local gallery of recent captures.

PRIVATE BY DESIGN
• Local by default. No analytics, no trackers, no servers of ours, no sign-in. Optional settings sync uses your own Firefox Account — preferences and presets only, never your screenshots.
• Uses activeTab — the page is only read when you start a capture.
• Optional network features are off by default and run only when you ask for them: downloading an extra OCR language file, Slack markdown (which only copies to your clipboard), and Cloud AI, which sends the capture you are editing to the AI provider you chose, using your own API key.

Open source libraries: Tesseract.js (Apache-2.0), face-api.js (MIT).