DevKitby FindUtils Buy DevKit
Browser extension · Chrome and Firefox

250+ developer tools,
one keypress from any tab.

DevKit puts them in your browser's side panel, and 15 of them work right on the page, on any site. Point at anything and hand it to your coding agent.

Buy DevKit $19.99 · lifetime opens the side panel
  • Paid once
  • Every update included
  • Up to 3 browsers
  • Edge, Brave, Opera and Arc load the Chrome build
A 40-second film with music and no speech. Alt, Shift and K open DevKit. The Inspector takes a card on a web page apart: its size, 240 by 184 pixels, its padding and gap, every style with its contrast, and copies it as Tailwind, JSX or CSS. Then Capture: the card and a button are pinned, the request "Make these match the design: 12px radius, 24px gap" is typed, and it is sent to the agent. Fonts, Dark mode, Edit text and the Outliner follow, and the other page tools are named. A pasted JWT, then JSON, then a cron line each get their answer in the side panel. 250+ developer tools. Claude Code asks to read a tab, the tab is approved, and it runs page checks and 209 offline tools, and picks up your briefs. DevKit by FindUtils, $19.99, lifetime.

01 — Page tools

Take any website apart without opening DevTools.

15 tools in a toolbar that opens on the page you are looking at, on any site. Nothing stays switched on behind your back.

Measure 7 tools

  • Inspector Styles and contrast for any element. Copy it as Tailwind, JSX or CSS.
  • Ruler Measure the distance between two elements.
  • Layout Flex and grid overlays, and the box model.
  • Colour picker Pick any colour on the page in HEX, RGB, HSL or OKLCH.
  • Outliner Outline every element by depth, and find what overflows the viewport.
  • Fonts See what font this is and every font in use. Try any Google font on the page.
  • Spec Spacing, colour and type matched to your design tokens, and the distance between two elements. Copy a red-line spec.

Change 4 tools

  • Dark mode Force a dark page: invert it with images kept, or use reading colours.
  • Edit text Type over any text on the page, with undo.
  • Move & delete Nudge elements with the arrow keys or hide them, with undo.
  • Replace image Swap an image or a background from a URL or a file, with undo.

Every switch turns off again Page edits have undo

Take away 4 tools

  • Picture-in-Picture Float a video over other windows, even when the page disables it.
  • Export element Copy an element as HTML + CSS, or as JSX + Tailwind. Open it in CodePen.
  • Save as PDF Save the page as a PDF.
  • Feedback Numbered notes on the page: copy a checklist, download a report, or send them to your agent. Copy checklistDownload reportSend to agent

02 — Capture

Point at it. Tell your agent what to change.

Pin elements on any page, write what should change, and DevKit hands your coding agent a brief: the selector, the styles, the markup and a picture of each element.

  1. 1Pin Click an element. Shift-click adds more, up to 20. Or drag an area.
  2. 2Ask Type what should change, or start from a prompt starter.
  3. 3Send Copy it as a prompt, or send it to a paired agent. The agent picks it up and reports done; you compare before and after.
The Brief card in DevKit's Inspector, with two elements pinned and a request typed.

Brief 2 pinned

Pinned 1button.primary2div.card
What should change Make these match the design: 12px radius, 24px gap
Prompt starters Match the designFix contrastMake it responsiveExplain how it's builtWrite a test

Copy as prompt AltC Send to agent ⌥S

  • Tweak Change the pinned element's colour, spacing, size or text live, undo any of it, and copy the change as a CSS or Tailwind diff.
  • Likely source In a development build, the brief carries the element's likely source file.
  • Errors Record a site's console errors and failed requests, and attach them to the brief.
  • Feedback notes Number your notes on the page, then copy a checklist, download a report, or send them to your agent.

03 — Paste anything

Paste it. The right tool answers.

DevKit recognises a JWT, JSON, a cURL command, a PEM block, a cron expression, a Unix time, a URL, a colour or Base64, and opens the matching tool with the answer ready. Try it here: nothing you paste leaves this page.

Try a sample
When it is not one tool

Recognised as a JWT, so the JWT decoder opened

Runs in this page: nothing you paste is sent anywhere.

JWT decoder Answer

Expired · exp is 30 Sep 2026, 16:40 UTC

signatureZk9bQm1xS3dQeU5sV3RIcg
signatureVerifiedfalse
expiredtrue
expiresAt2026-09-30T16:40:00.000Z

04 — Your coding agent

Hand DevKit to Claude Code or Codex.

A local bridge, off until you turn it on. Your agent runs DevKit's 209 offline tools, reads a tab only after you approve it, and picks up the briefs you send from the page.

What your agent can do

  • Run 209 offline toolsFormatters, converters and decoders on its own input. No page, no network.
  • Check a tab you approveAn accessibility audit, SEO and meta tags, page speed, the site's stack, a screenshot.
  • Pick up your briefsWhat you pinned and asked for, with a picture of each element.
  • Read an element backIts styles or a fresh picture, to check its own work.

Settings Agents Connect an agent

5 of 5 checked

  1. Step 1Turn on the agent bridge
  2. Step 2Choose your agent and what it may do
  3. Step 3Download the helper
  4. Step 4Run one command
  5. Step 5Restart your agent and say hello
curl -fsSL https://findutils.com/devkit/install.sh | sh -s -- connect --extension-id <id> --code "<six words>" --client claude-code
Step 4 shows this command with your id and six words filled in. It fetches the helper from findutils.com, checks it, and pairs your agent.

WHAT IT NEEDS

  • macOS or Linux
  • No Node.js: the command installs the helper
  • A Chromium browser or Firefox

05 — More in DevKit

A network panel, mobile checks, recipes and offline packs.

A DevTools panel

DevKit adds its own panel to DevTools. Watch requests arrive, import and export HAR files, copy any request as cURL, or open it in DevKit to replay it.

Mobile checks

A responsive viewer, safe areas, PWA checks and deep-link checks. See your page at phone sizes before you ship it.

Chains and saved recipes

Send one tool's output straight into the next. Save a chain you use often as a recipe and run it again in one step.

  • Image Compress Compress and convert images. Resize, compare, batch and ZIP. WebPAVIFJPEGPNG
  • HEIC Convert iPhone HEIC and HEIF photos to JPEG or PNG.
  • PDF Tools Work on the pages of a PDF. MergeSplitRotateReorderDelete pagesPage numbersWatermarkExtract text
  • SQLite Browser Open a .sqlite or .db file read-only: tables with row counts, run SQL, export CSV or JSON.

Heavy files, handled on your computer

4 heavy tools come built in and load only when you open one: compress images, convert HEIC photos, work on PDFs or open a SQLite database.

Files never leave the machine

Shortcuts

Your hands stay on the keyboard.

Open the side panel and paste. DevKit recognises what you pasted and opens the matching tool with the result already on screen.

Open the side panel

From any tab. Paste, or search all 274 tools by name.

Open the Inspector

Straight onto the page you are looking at. Hover an element to see its box, spacing and styles.

Search from the address bar

Type fu in the address bar and the tool name. DevKit's search answers there.

  • Alt / ⌥ C Copy the element under the pointer as a prompt
  • Alt / ⌥ S Send the brief or the notes to your agent

Privacy

Works offline. No account. No telemetry.

The tools run inside your browser. What you paste and the pages you inspect stay on your computer.

Nothing else leaves your browser: no pages, no URLs, no pasted text, no usage data.

AT INSTALL

The permissions DevKit asks for

storage
Keeps your settings, favourites, recipes and history on this computer.
activeTab
Lets a tool read the tab you are on, when you use it there.
scripting
Runs the page tools on that tab.
contextMenus
Adds DevKit to the right-click menu.
sidePanel
Opens DevKit in Chrome's side panel.
Chrome only

Everything else is optional. The tool that needs it asks for it, when you use that tool.

Pricing

Pay once. Keep every tool and every update.

DevKit licenceOne-time purchase

$19.99lifetime

Paid once. No subscription, and every update is included.

  • Every tool: all 274, the 15 page tools included
  • Every future update
  • Up to 3 browsers per licence
  • Chrome and Firefox builds
Buy DevKit

No subscription, no trial and no refunds. Checkout is a secure Stripe page. Terms of sale

From install to the side panel

  1. 01 Coming soon Install DevKit from the Chrome Web Store or Firefox Add-ons Both store listings are on the way.
  2. 02 Buy on findutils.com One payment covers the licence.
  3. 03 Get your key It is shown as soon as you have paid, and we email it to you too.
  4. 04 Paste it into DevKit Open the Activate screen in the extension and paste the key. Use it in up to 3 browsers.

Questions

Before you buy

Something not answered here? Write to us from the contact page.

Which browsers does DevKit run in?
Chrome and Firefox. Edge, Brave, Opera and Arc install the Chrome build.
Do I need an account?
No. You buy, get a key and paste it into the Activate screen.
Is it a subscription?
No. DevKit is $19.99 once, for life, with every tool and every update.
Is there a free trial?
No. The tools on findutils.com stay free to use in your browser, so you can try them there first.
Can I get a refund?
No. All sales are final. There are no refunds, except where the law requires one. The tools on findutils.com are free, so you can try them before you buy.
How many browsers can I use?
Up to 3 browsers per licence.
Where is my key?
It is shown as soon as you have paid, and emailed to the address you paid with. The page shows it for 24 hours; after that it is in your mailbox, and we can email it again. Lost your key?
What does DevKit send home?
Only the licence check: your key and a random browser id. There is no telemetry, and it works offline.
What does DevKit ask for when I install it?
Storage, activeTab, scripting and the right-click menu, plus the side panel on Chrome. Everything else is optional: the tool that needs it asks when you use it.
What does my agent get when I send a brief?
The page's address and title, your request, and for each element you pinned: its selector, its styles, its trimmed markup and visible text, and a picture of it. What was typed into form fields is left out. The agent picks the brief up when you ask it to; DevKit pushes nothing.
Can my coding agent change my pages?
Not by default. A new pairing can run DevKit's offline tools and read-only page tools, on a tab you approve. Only the "Use website tools (WebMCP)" scope, chosen when you pair, lets an agent use a site's own tools, and those may change things on that site.

Every tool, on every tab, from now on.

Paid once. Every update included. Up to 3 browsers.

Buy DevKit $19.99 · lifetime