Add to Chrome

Website change monitoring · Chrome extension

Watch the pages.
Catch the changes.

Monitor web pages for price changes, AI product updates, and new listings. Start free in Chrome without an account. Add AI summaries to explain changes, or sign in for cloud checks that continue after Chrome closes.

Add to Chrome View a sample report

Free browser watches · No account required · Chrome 114+

EXAMPLE / AI PRICE SUMMARY Cloud active
P
SOURCE PAGE Noise-cancelling headphones shop.example / product / 1048
WATCHING FOR

Track the price and stock status. In the summary, note whether the price is below $300.

LATEST CHANGE

$349→$289

−17.2%
Illustrative check NEXT / 56 MIN
01Compare
02Explain
CloudScheduled checks after Chrome closes
1Plain-language instruction
∞A timeline you can revisit
AIOptional change summaries

How it works

From an open page to a change history.

Describe what to watch, choose a schedule, and compare changes. Add optional AI analysis to explain the results.

  1. 01

    Open the page

    Open a page you can access and click PageLens. Grant site permission so the extension can capture its visible text.

  2. 02

    Say what matters

    Write a short monitoring instruction, choose a checking schedule, and save. Browser checks compare visible text; optional AI analysis uses your instruction to explain the result.

  3. 03

    See the change

    Review the first capture as your baseline, then compare later checks. Keep Chrome running and your computer awake for browser watches, or use a cloud watch.

What would you watch?

One lens. Very different signals.

Choose the source pages you care about. Keep a record of their changes, with optional AI summaries to help you review.

01 / Models & token rates

AI API pricing

Watch an AI provider’s published pricing page for changes to input, output, and cached-token rates. Keep the model name, currency, and billing unit in view. AI API price monitoring guide →

Daily watchIllustrative check
EXAMPLE MODEL / PRICE HISTORY EXAMPLE
PUBLISHED RATE CHANGEOutput rate: $10 → $12

Illustrative USD rates per 1M tokens. Check the source for billing conditions.

$10 +20%
INPUT $2OUTPUT $12CACHED $0.50
02 / Price, volume & moves

Bitcoin

Track the BTC price, daily change, and volume shown on your source page. Compare scheduled captures and use optional AI summaries to review the numbers.

Hourly watchIllustrative check
BTC / USD EXAMPLE RUN
CURRENT PRICE$68,420+4.8% / 24H
AI

The 24-hour move crossed 4%. Reported volume also rose since the previous check.

03 / Models, APIs & tools

An AI changelog

Follow model launches, coding-agent updates, and API deprecation notices on an official changelog. Compare captures and use optional AI summaries to review what changed. AI release monitoring guide →

Daily watchIllustrative check
AIDeveloper changelogExample product · page updatesILLUSTRATION
01

A new model is listed with its availability and supported inputs.

MODEL RELEASE
02

An API migration notice adds a retirement date for an older version.

API UPDATE
03

Review the original announcement before changing your integration.

SOURCE CHECK
AI

Optional summary: a model addition and an API migration notice to review.

04 / Price & availability

A product price

Keep a history of listed prices and stock messages. Compare checks, and use an optional AI summary to interpret a price change or a return to stock.

Hourly watchIllustrative check
shop.exampleIN STOCK
Noise-cancelling headphones
PRICE DROP DETECTED
$349→$289
−17.2%

Below your $300 target and available to order.

SEP 18SEP 19SEP 20SEP 21
05 / Plans, limits & features

Competitor pricing

Keep a history of a competitor’s public SaaS pricing page. Review changes to plan prices, included usage, and features before updating your comparison. Competitor price monitoring guide →

Daily watchIllustrative check
PTeam planExample SaaS · pricing pageILLUSTRATION
01

The monthly plan price changed from $20 to $25 per seat.

PRICE CHANGE
02

Included usage changed from 1,000 to 1,500 requests per seat per month.

USAGE LIMIT
03

Annual billing terms are listed separately. Review them on the source page.

SOURCE CHECK
AI

Optional summary: the monthly price rose 25%, alongside a higher usage allowance.

Illustrative data and AI summaries shown. Browser change alerts are based on captured text changes. AI can discuss a price target in its summary; a written target does not filter those alerts. Checks run on a schedule and depend on source-page access.

Boundaries by design

It watches only what you ask it to.

PageLens is designed around explicit page access and narrow monitoring instructions—not broad account access.

Read the install notes ↓
  • 01
    Per-site permission

    Signed-in pages require permission for that site. Optional cookies are encrypted and kept for no more than three days.

  • 02
    Sensitive fields stay out

    Password inputs, form values, hidden content, scripts, styles, and URL query parameters are excluded from public results.

  • 03
    Security checks are respected

    PageLens stops for CAPTCHA, MFA, device confirmation, or an expired sign-in instead of trying to bypass them.

SIMPLE PLANS

Start free in your browser. Move important watches to the cloud.

Local means this Chrome browser. Cloud watches keep checking when Chrome is closed.

01 · NO ACCOUNT

Browser

Free forever

  • Unlimited browser watches
  • Task settings stay in this browser
  • Checks and alerts while Chrome runs
Start without signing in ↗
02 · SIGNED IN

Free account

More continuity, no charge

  • Everything in Browser
  • Optional task backup and device restore
  • 1 cloud watch, running after Chrome closes
Get PageLens ↗
03 · PAID ACCOUNT

Paid

For every watch that needs the cloud

  • Everything in Free account
  • Unlimited cloud watches
  • Checks continue after Chrome closes
Ask about access ↗

Browser watches compare visible page text. Account backup includes settings and instructions; page content and run history stay on the device.

PageLens for Chrome

Make your first page a watch.

Install PageLens from the Chrome Web Store and create unlimited browser watches without signing in. Sign in when you want a cloud watch or task backup.

Install from Chrome Web Store Chrome Web Store · Free browser watches · Chrome 114+

Can't access the store? Install from a file.

Download PageLens ZIP ↓
Manual installation steps
  1. Unzip the package and keep the PageLens folder somewhere you will not move it.
  2. Open Chrome Extensions and turn on Developer mode: chrome://extensions/
  3. Choose “Load unpacked,” select the folder containing manifest.json, and pin PageLens to the toolbar.
Prefer to run watches on your Mac? Install PageLens Local →
  1. 01
    Open the Chrome Web Store

    Visit the PageLens — Page Change Monitor listing in Chrome.

  2. 02
    Add PageLens to Chrome

    Click “Add to Chrome,” then confirm “Add extension.”

  3. 03
    Pin it and start a watch

    Pin PageLens from Chrome's Extensions menu, open a page, and tell it what to watch.

Prompt copied