API Payload Debugger

Repair, compare, analyze, and generate TypeScript types from API payloads instantly. All processing runs locally.

Detailed Description API Payload Debugger is an all-in-one JSON toolkit built for developers, QA engineers, testers, and API teams. Repair malformed JSON, compare payloads, generate TypeScript interfaces, decode JWTs, query with JSONPath, and convert formats — all directly inside your browser with zero data collection and zero external servers. Everything runs locally. No analytics. No tracking. No background requests. No permissions required. Features Repair & Format JSON Fix malformed JSON instantly: Trailing commas Single quotes Unquoted keys Smart quotes JavaScript comments Invalid escape characters Then: Format JSON Minify JSON Sort object keys Escape/unescape stringified payloads Analyze Payloads Inspect large responses quickly: Detect inconsistent field types Find oversized payload paths Measure payload size (Bytes / KB / MB) Perfect for debugging API responses and optimizing contracts. JSONPath Query Support Run powerful JSONPath queries: $.users[*].email $..id Recursive selectors Filters and slices Copy matched paths instantly. Mask Sensitive Data Sanitize payloads before sharing: Mask keys by name Regex-based masking Replace values with [masked] Remove sensitive fields entirely Useful for logs, tickets, bug reports, and screenshots. Structural JSON Diff Compare two payloads side-by-side: Added fields Removed fields Changed values Type mismatches Built for API debugging and regression analysis. Generate Developer Types Generate code from sample JSON: TypeScript interfaces Zod schemas JSON Schema (Draft-07) Supports nested arrays, optional fields, and unions. Convert Formats Convert JSON into: YAML CSV URL query strings Fast, clean, and copy-ready. Interactive Object Paths Explore payload structures visually. Copy usable access paths like: users[0].profile.name Great for debugging and testing. JWT Decoder Decode JWT tokens locally: Header Payload Expiration Issued-at timestamps Valid/expired indicators Supports tokens with or without Bearer. NDJSON Support Automatically detects and processes newline-delimited JSON (NDJSON). Privacy First This extension is fully local-first. Permissions No permissions required No host permissions No optional permissions Data Collection No analytics No telemetry No tracking No data collection Remote Code No remote scripts, CDN imports, or external runtime code. The extension operates entirely inside the browser. Built For Backend Developers Frontend Developers QA Engineers SRE / DevOps Teams API Testers Security Researchers Tech Stack Built with: React TypeScript Vite jsonrepair One-Line Promo Tagline Everything you do to JSON — locally, privately, in one tab. Privacy Practices (Important for Google Submission) Single Purpose Description Provides local JSON debugging, formatting, repair, conversion, comparison, and schema generation tools for developers. Remote Code Justification This extension does not use remote code. All scripts, assets, and application logic are bundled locally within the extension package. Data Usage Certification This extension: Does not collect user data Does not transmit data externally Does not sell or share data Does not use analytics or tracking Release Notes (What's New) Initial release featuring: JSON Repair JSON Formatter JSONPath Query Payload Diff Type Generation JWT Decoder Format Conversion Sensitive Data Masking