Exception Message Generator
Generates a plausible, fictional exception message — the kind of text an error-handling test, log viewer mockup, or documentation screenshot needs without pulling a real stack trace.
What you'll get
This generator draws from a hand-checked list of 18 entries. Here is a spread of 6 of them, so you can see the style before you generate:
- NullReferenceError: Cannot read property 'id' of undefined
- ConnectionRefusedError: Could not reach service at port 5432
- PermissionDeniedError: Caller lacks required 'write' scope
- RateLimitExceededError: Too many requests in the last 60s
- TokenExpiredError: Session token expired 4 minutes ago
- SchemaMismatchError: Payload does not match expected shape
A fixed sample of the list, not a live draw — your own results are picked at random from all 18, without repeating until the list runs out. Original authoring for Generate Random — fictional, framework-neutral exception text.. Last reviewed 2026-07-18.
How to use this tool
- Press generate for a message.
- Generate again for a different one.
Common use cases
- Error-handling UI mockups
- Log-viewer test fixtures
- Documentation screenshots
Practical tips
- A good message says what was expected as well as what happened; "invalid input" tells whoever reads the log nothing.
- Never put user data or secrets in an exception message — it will end up in a log aggregator you do not control.
Entries are chosen with your browser's cryptographic random number generator, so every entry on the list is equally likely. How Generate Random works.