JSON Validator for Software Developers
Catch JSON syntax errors before they break your application. Validate configuration files, API payloads, and test fixtures with precise, line-level error reporting.
Software developers work with JSON daily in configuration files (package.json, tsconfig.json), API integrations, mock data for tests, and inter-service communication. A quick validation step prevents runtime errors, failed deployments, and hours of debugging caused by a single misplaced comma.
Preventing Deployment Failures
A single trailing comma in a JSON config file can cause a deployment to fail silently or crash on startup. By validating configuration files before committing, you catch these issues at the earliest possible stage, long before they reach staging or production environments.
Validating Test Fixtures
Unit and integration tests often rely on JSON fixture files for mock data. If a fixture contains invalid JSON, the test framework throws a parse error that can be confusing to diagnose, especially in large test suites. Validating fixtures as part of your workflow ensures tests fail for the right reasons.
Frequently Asked Questions
Yes. These files use standard JSON (tsconfig.json supports JSONC with comments, which the validator also handles). Paste the file contents and get instant feedback on any syntax issues.
For automated validation, use the UnicornToolbox CLI or add a JSON lint step using tools like ajv-cli or jsonlint in your CI configuration. This web tool is ideal for quick, ad-hoc checks during development.