Available nowPro

Know when a site’s design changes for real

Add a URL to a project and designlang re-reads it daily, every three days or weekly. It stores a new snapshot and emails you only when a change survives a second look, so measurement noise does not wake you up.

Add a monitorSee pricing
A flat line with one step up, followed by a confirmed-change alert.Primary colour changedConfirmed on a second read
Dailyto weekly checks
10 / 25 / 100monitors on Pro / Team / Agency
1 creditper check

How it works

From a saved project to a result, in four steps.

  1. Add a monitor

    Pick a project, a URL and a cadence. The address is checked for safety again each time a scheduled run starts, not only when you create the monitor.

  2. Check and compare

    The worker reads the page and compares it with the last snapshot in OKLab colour space, with thresholds that ignore tiny shifts.

  3. Confirm before alerting

    If something looks different, the worker runs the page again. The confirm re-run is free to you. Only a change both reads agree on is stored and alerted.

  4. Read the alert

    The email names the change in roles, such as “primary colour changed”, and links to the compare view. Alerts are batched, and Slack is available on the integrations page.

Where it helps

Your own production site

Catch a stray stylesheet or a token that drifted from the design system.

Client sites

Know when someone else edits a site you maintain.

Competitors

Watch a launch page without opening it every week.

Limits. A monitor checks the public page a visitor gets. Sites that block automated browsers can stop a monitor. After repeated failures it shows “Can’t reach” and you get one email, not one per attempt.

Questions, answered

How do you avoid false alerts?
Two things: thresholds that ignore sub-visible differences, and a confirm re-run that must agree before anything is stored or sent.
What happens if my credits run out?
Monitors pause with a quota status and you get one email. Data is never deleted, and checks resume when credits return on the 1st (UTC).
How often can a monitor run?
Daily, every three days or weekly. The shortest interval your plan allows is shown when you create the monitor.
Can I publish the changes?
Yes. A project can publish a public changelog with an RSS feed, generated from confirmed changes.

More from designlang

All features
Pro

Time Machine

Read a site’s design system from the Internet Archive and see every rebrand on a timeline.

Pro

Design Debt Score

A 0 to 100 score for how much of a site’s styling resolves to a design token, with a ranked fix list and a trend line.

Pro

Brand Context

Serve a saved project’s tokens and rules to Claude Code, Cursor and any MCP client, and check code against them.

Try Monitoring now

Free accounts get 3 live runs. Pro is $9 a month with 200 credits.

Add a monitorRead the guide