Chrome Extension · Free · Open source

Annotate and edit
the web.

A browser extension that lets you erase distractions, highlight what matters, drop notes, and resize layouts on any site. Every change persists across visits — and never leaves your machine.

Add to Chrome View on GitHub See it in action
arstechnica.com/gadgets/2026/04/mark-it-up
Adnota
ARS TECHNICA
Mark it up. Block it out. Make it yours.
April 19, 2026 · 5 min read

For years, browsers have been read-only. You visit a page, you consume it, you close the tab. Nothing you noticed, flagged, or disagreed with stays.

A new generation of extensions is pushing back. They let you annotate, erase, and reshape any page — privately, persistently, on your device. No cloud. No accounts.

The real shift isn't the tools themselves. It's the premise: the web should be a document you can edit, not a billboard you're asked to politely consume.

180 × 200
📢
Advertisement
300×250
04/19/26

Zero cloud. Zero accounts.

Everything lives in your browser's local storage. No servers, no accounts, no data ever leaving your machine.

Persistent across every visit.

Annotations restore automatically on the next visit — erased elements stay erased, highlights stay lit, notes stay anchored.

Your canvas, your rules.

Erase clutter, highlight insights, drop notes, draw freely, resize layouts. The entire web becomes your workspace.

See it in action
The Toolkit

Four tools.
One canvas.

Adnota ships with four purpose-built tools, each solving a distinct problem with the web as you read it. Every annotation is anchored intelligently — surviving page refreshes, SPA navigations, and layout shifts.

🗑

Eraser

Permanently hide any page element. Hover to preview, click to erase. Scroll the mouse wheel to walk up the DOM and find the exact container you want gone. Ad-detection promotes erasures domain-wide automatically.

Lorem ipsum dolor sit amet
consectetur adipiscing elit
sed do eiusmod tempor
210×120
▣ likely ad · ad-keyword
📝

Sticky Notes

Drop anchored text annotations anywhere on the page. Notes survive layout shifts using a multi-signal fuzzy anchor system — CSS selector, text fingerprint, structural context, and geometry scoring.

Lorem ipsum dolor sit amet
consectetur adipiscing elit
sed do eiusmod tempor ut
labore et dolore magna aliqua
04/19/26
Follow up on this!
04/22/26
Check source
✏️

Highlight & Draw

Text highlights via the CSS Custom Highlights API — zero DOM mutation, React-safe. Freehand pen, arrows, rectangles, ellipses, and text boxes overlay any page. Black mode = instant redaction.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor. Ut labore et dolore magna aliqua ut enim.
↔️

Resizer

Resize, move, or restyle elements. Sidebars too wide, panels in the wrong place, text too small — drag handles to resize, drag-and-drop to reposition, recolor with the EyeDropper, or scale text with Aa± chips.

480×320
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed.
The Scratch Pad

For the long
conversation.

Every highlight and note from the page you're on, side-by-side in one quiet panel. Built for ChatGPT threads, Claude conversations, and longform reads where scrolling back is the friction you're trying to escape.

Just the words you saved — paragraph breaks intact.
Filter by Highlights, Notes, or Tags — select what you want
Goto any source. Copy one, or all of them at once.
Your Personal Knowledge Base

Every annotation.
Every site.
All in one place.

As you annotate the web, Adnota silently builds a searchable history of everything you've highlighted, noted, erased, and drawn — across every site you've ever visited.

The My Edited Sites dashboard gives you a live view of your entire annotated web — sortable, filterable, and one click away from any page you've touched.

See every site you've annotated at a glance
Filter by notes, highlights, erasures, strokes
Jump back to any annotated page instantly
Search & sort across your entire annotated web
Adnota
Adnota
My Edited Sites
Filter sites...
21 Sites 253 Edits 33 Pages 338 KB / 10 MB · 3%
A
arstechnica.com
1 page · 1h ago
+2 Notes +1 Highlight
Visit
Y
news.ycombinator.com
2 pages · 47m ago
+2 Notes +5 Strokes
Visit
G
www.google.com
2 pages · 46m ago
+7 Erased +12 Highlights
Visit
W
en.wikipedia.org
1 page · 3h ago
+2 Notes +4 Strokes
Visit
N
www.nytimes.com
1 page · 2h ago
+2 Erased
Visit
+ 16 more sites
How it works

Install once.
Own the web forever.

1

Install from Chrome Web Store

One click, no account, no sign-in. The extension injects itself into every page you visit, invisibly, until you need it.

2

Annotate any page

Click the dock or use keyboard shortcuts. Erase distractions, highlight what matters, drop notes, resize layouts.

3

Come back to your canvas

Every annotation auto-restores on the next visit. Your edited web stays edited — silently, privately, persistently.

No accounts

Nothing to sign up for. Nothing to log into. The extension works immediately.

No cloud

All data lives in chrome.storage.local. Never leaves your browser.

No tracking

No analytics, no telemetry, no usage data collected. What you annotate is yours alone.

Open source

Every line on GitHub, MIT-licensed. Inspect in DevTools, fork it, or run it yourself.

Adnota's core is free, forever. If we ever charge, it'll be for opt-in extras like cross-device sync — the local, private experience you see today will always be free.

From the founder

I built Adnota because every other annotation extension wanted my email, my account, my data. I just wanted to erase a sidebar and have it stay erased.

So I made the tool I wanted — local, private, no servers to break, no company to sell to. If it's useful to you too, that's the whole point.

And it's MIT-licensed and fully open source — read every line, fork it, or run it yourself.

Is it a work in progress? Yes. Does it have potential? I think so — and what comes next is shaped by who shows up.

— michael@adnota.app
Feature Requests

Help shape
what we build next.

Adnota is pre-launch and actively seeking input. Vote on the features you want most — every vote shapes the roadmap.

Or just email us directly
Report a bug Suggest an idea Anything else