Assert vs Checkly
Checkly runs synthetic monitoring and browser checks, and you write its assertions in JavaScript or TypeScript. Assert monitors APIs, and you build the assertions by clicking.
Overview
| Feature | Assert | Checkly |
|---|---|---|
| Focus | API monitoring with response validation | Synthetic monitoring & browser checks |
| Pricing | Starts free, priced per monitor | Priced on check runs |
| Setup | 2-minute setup, no code required | Playwright scripts |
| Response Validation | Built-in JSONPath assertions | Via custom scripts |
| GraphQL | First-class support | Via HTTP checks |
When to choose Assert
Choose Assert if you:
- Need deep response body validation without writing code
- Want simple, predictable pricing
- Focus primarily on API health (REST + GraphQL)
- Prefer a quick setup to writing scripts
- Need multi-region monitoring from 6 locations
When to choose Checkly
Choose Checkly if you:
- Need browser/E2E testing alongside API monitoring
- Want to write custom Playwright scripts
- Need complex multi-step transactions
- Require detailed browser performance metrics
Feature comparison
Response validation
Assert: The assertion builder is point-and-click. You validate JSON paths, status codes, headers, and response times without writing code.
$.user.status == "active"
$.data.items.length > 0
responseTime < 500ms
Checkly: You write the assertions in JavaScript or TypeScript, in Checkly's check editor.
Pricing model
Assert: The free tier includes the core features. You pay per monitor, not per check run, so the monthly cost is predictable.
Checkly: You pay for the check runs you consume, so cost scales with frequency. Browser checks cost more than API checks.
Multi-region
Assert: 6 regions included, select per-monitor
Checkly: 20+ regions, which affect the price
Scripts or point-and-click
Checkly is the fit when your API checks sit next to browser tests and multi-step transactions.
Assert is the narrower tool: point-and-click assertions on the JSON, 6 regions included, and pricing per monitor rather than per check run.
Try Assert free — no credit card required.
