NerdTools Fast, free online tools for sysadmins, developers, and nerds.

Catch visual regressions before your users do.

Know exactly when your website's appearance changes. Capture screenshots automatically, compare against baselines, and catch visual bugs before your customers do.

Free forever plan
No credit card required
Smart pixel comparison

Join thousands of developers who trust NerdTools to watch their sites 24/7

Automated captures
Baseline comparison
Instant email alerts
Configurable tolerance

See what you've been missing

Catch visual regressions that automated tests simply can't detect.

Baseline Snapshots

Set a "known-good" screenshot as your baseline. We'll compare every new capture against it to spot changes instantly.

Smart Comparison

Our intelligent algorithm ignores minor rendering differences while flagging meaningful visual changes.

Flexible Scheduling

Choose how often to capture—from every few minutes to daily. Match frequency to your deployment schedule.

Capture History

Browse a timeline of past screenshots up to 30 days. See exactly when changes occurred and compare any two captures side-by-side.

Privacy Controls

Keep screenshots private. Privacy is key to our infrastructure design ensuring only you have access to your data.

Email Alerts

Get notified the moment a visual change exceeds your tolerance threshold. No more discovering broken layouts days later.

Spot the difference instantly

Our comparison view highlights exactly what changed between captures.

Visual diffs that make sense

When something changes, we don't just tell you—we show you. Side-by-side comparison with pixel-perfect highlighting of differences. No more hunting through screenshots to find what broke.

Try It Free
4.2% difference detected

Set up in minutes, not hours

Getting started is simple. No complex configuration required.

1

Add Your URL

Enter any webpage you want to monitor. Works with public sites and password-protected pages.

2

Set Your Baseline

Capture your first screenshot and mark it as the "known-good" baseline for future comparisons.

3

Configure Alerts

Set your tolerance threshold and schedule. We'll email you when changes exceed your limits.

4

Relax

We watch your pages 24/7. Review captures anytime and update baselines as your site evolves.

Why pay when you can get it free?

Everything you need and more, without the enterprise price tag.

Features
Free
Free
Essential monitoring, no cost
Solo
£7.50/mo
For personal projects and freelancers
Plus
£30.00/mo
Most popular
Best value for growing teams
Premium
£90.00/mo
Maximum insight at maximum speed
Uptime monitors
2
from 15 mins
15
from 5 mins
100
from 1 min
250
from 30 secs
Server monitors 1 8 60 150
Screenshot monitors
1
from 12 hours
3 day history
5
from 1 hour
7 day history
30
from 10 mins
14 day history
100
from 5 mins
30 day history
DNS redirects 1 10 75 150
Short links Unlimited Unlimited Unlimited Unlimited
Email alerts

Frequently asked questions

Everything you need to know about Screenshot Monitoring.

Yes! We offer a limited screenshot monitoring service completely free. More features are available in our paid plans.

We capture screenshots on your schedule and compare them against your baseline image. You set a tolerance threshold—changes below that percentage are ignored, while larger differences trigger alerts.

You control the sensitivity. Set a tolerance percentage (e.g., 1%, 5%, 10%) and we'll only alert when changes exceed that threshold. Perfect for ignoring minor rendering differences while catching real issues.

We retain your capture history for 30 days. Old captures beyond our retention period are automatically purged.

Stop guessing. Start seeing.

Join developers and QA teams who trust NerdTools to catch visual bugs.
Free forever. No credit card required.