Testers
Browse our free collection of testers. All tools run locally in your browser for maximum privacy.
Testers are the validation layer between 'I think this works' and 'I know this works.' This category covers regex validation, JSONPath queries, cron expression verification, schema validation, and protocol testing, the tools that catch bugs before they reach production.
Common Workflows & Recommended Tools
Build and test a regex pattern against edge cases in real time
→ Regex TesterVerify a JSONPath expression before committing a Postman assertion
→ JSONPath TesterValidate a cron expression and preview the next 10 fire times
→ Crontab GeneratorTest a WebSocket connection and inspect message frames
→ WebSocket TesterVerify a webhook endpoint receives the expected payload
→ Webhook TesterCommon Mistakes to Avoid
- ✗Testing regex only against happy-path inputs, edge cases like empty strings, unicode, and nested delimiters are where patterns break.
- ✗Confusing JSONPath with JMESPath, both query JSON but use different syntax; AWS uses JMESPath, kubectl uses JSONPath.
- ✗Writing cron expressions without testing, a wrong day-of-month vs day-of-week combination can fire daily instead of monthly.
- ✗Testing WebSockets only in Chrome and discovering Safari-specific close-code behavior in production.
Privacy-First by Design
Test data often includes production payloads with PII, API keys, or internal URLs. Browser-based testers ensure your test data never leaves your machine, paste any payload safely.
Frequently Asked Questions
Can I test regex patterns with production data safely?
Yes. All regex testing runs locally in your browser. Your test strings and patterns are never sent to any server.
Does the cron tester support both 5-field and 6-field (seconds) formats?
The tester supports standard 5-field POSIX crontab syntax. For 6-field extensions with seconds, check whether your target system (e.g., Quartz, Spring) uses the same extension.
Can I test WebSocket connections to localhost?
Yes. The WebSocket Tester connects to any ws:// or wss:// URL, including localhost and private network addresses, directly from your browser.