Compare Multiple JSON Files On Your Machine
The only free tool to compare multiple JSON files locally — no uploads, no servers. Everything runs in your browser, so your data never leaves your machine.
Why Developers Choose PolyJSON
Compare Multiple JSON Files
Compare 3, 4, or 5 JSON files at the same time. Go beyond simple two-file diffs and see how all your configs relate — all on your local machine.
Semantic JSON Diff
Understands JSON structure. Compares keys and values semantically, not just line-by-line text differences.
Config Drift Detection
Compare configuration files across Dev, Staging, and Production environments to spot inconsistencies before they cause outages.
Instant Local Comparison
Paste your JSON and get results immediately on your machine. No waiting, no processing queues, no file size limits.
Runs on Your Machine
All JSON comparison happens locally in your browser. Your data never leaves your machine — zero server uploads, fully offline-capable.
Free & No Signup
Compare JSON files for free with no account required. No rate limits, no feature gates, no tracking.
How It Works
Paste Your JSON
Paste JSON into side-by-side panels. No file upload needed — everything stays on your local machine.
Compare Instantly
Diff appears automatically when two or more panels have valid JSON. Add up to 5 panels to compare multiple files at once.
Review Differences
See additions, removals, and changes highlighted with line-level and word-level diffs. Sort keys, hide unchanged lines, and switch views.
Use Cases
Environment Config Auditing
Compare multiple JSON config files across dev, staging, and production locally to ensure consistency and catch drift before deployment.
API Response Comparison
Compare JSON API responses across different versions or endpoints on your machine. Verify backward compatibility without uploading sensitive data.
Infrastructure as Code Review
Diff Terraform state files, Kubernetes manifests, or CloudFormation templates across environments — all locally in your browser.
Translation File Validation
Compare multiple i18n/l10n JSON files across languages to find missing keys, extra keys, or value mismatches without leaving your machine.
Ready to Compare JSON Files?
Compare multiple JSON files locally in seconds. No signup, no installation, no uploads — everything runs on your machine.
Open PolyJSON Tool