TL;DR - Calibre
- Calibre is a web performance monitoring platform for continuous speed testing
- It tracks Core Web Vitals, runs synthetic tests, and provides performance budgets
- Plans from $45/month
Pricing: Paid only
Best for: Enterprises & professionals
Score: 82/100
Pricing Plans
15-day free trialStarter
$50/month
Small teams
- Performance monitoring
- Core Web Vitals
- Alerts
- Basic features
Most Popular
Team
$150/month
Teams
- More tests
- API access
- Integrations
- Priority support
Business
$350/month
Large teams
- Unlimited tests
- SSO
- SLA
- Dedicated support
About Calibre
Calibre measures web performance and tracks it over time. Not just page load metrics—Core Web Vitals, accessibility scores, and performance budgets that alert you when sites get slower.
Synthetic monitoring tests from multiple locations. Competitive benchmarking shows where you stand. Historical data reveals performance trends.
Teams serious about web performance use Calibre to maintain speed over time, catching regressions before users notice.
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Calibre FAQ
Yes, Calibre is completely free and open source. GPL license. Best e-book management software.
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