Manifest V3 · 100% on-device

The web developer’s toolbox, reimagined.

Inspect, outline, edit and audit any page from one keyboard-friendly popup. Over 50 focused tools — a color picker, ruler, live CSS editor, form filler and rich reports — all running privately in your browser.

No sign-upNo trackingFree & open
WebDev Toolbox
2 active on this tab
Search tools…
DisableCSSOutlineImages
Disable All StylesTurn off every stylesheet
Outline HeadingsLabel all h1–h6
Display Image DimensionsOverlay rendered sizes
Element InformationHover to inspect
Color PickerSample any pixel
RulerMeasure the page

Everything you reach for, in one place

A curated set of the most useful web developer tools — grouped, searchable and one click away.

CSS control

Disable all, linked or inline styles, switch to the border-box model, reload stylesheets, or live-edit CSS in a side panel.

Outline & structure

Outline block elements, headings, tables, positioned elements and external links to see a page's skeleton instantly.

Image auditing

Reveal alt text and dimensions, outline images missing alt, hide images, and find broken images in one click.

Form superpowers

Populate every field with sample data, clear forms, reveal passwords, enable disabled fields, and flag inputs without labels.

Element inspector

Hover any element for a docked panel with its box model, computed styles and ancestor breadcrumb.

Color picker

Sample the exact color of any pixel on the page and copy the hex with a click.

Ruler & guides

Draw a measuring rectangle or drop draggable alignment guides across the viewport.

Rich reports

Open searchable reports for CSS, images, forms, colors, document outline, response headers and more.

Cookies & privacy

View, add and delete cookies, and toggle JavaScript, popups, images or notifications per site.

Privacy first

Your work stays yours

WebDev Toolbox was built privacy-first from day one. There are no accounts and no network calls except the ones you explicitly trigger — like opening the W3C validator.

No tracking, ever

Zero analytics, zero telemetry, no remote code. The extension never phones home.

Runs on your device

Every tool executes locally in your browser. Your pages and data never leave the machine.

Minimal permissions

Only the browser capabilities each tool genuinely needs — and nothing is stored in the cloud.

// manifest.json — permissions
"permissions": [
  "storage", "scripting", "tabs",
  "cookies", "contentSettings",
  "browsingData", "activeTab"
]

// network requests at rest: 0

Up and running in seconds

No configuration required. It just works on every tab.

01

Install the extension

Add WebDev Toolbox to Chrome. It sits quietly in your toolbar until you need it.

02

Open the popup

Click the icon or use the keyboard. Search across every tool or browse by category.

03

Toggle & inspect

Flip tools on and off per tab. A badge shows how many are active, and “Reset page” clears them all.

Ready to build faster?

Add WebDev Toolbox to Chrome and get every tool you need — for free, forever.

Add to Chrome — it’s free