JASON (JSON Manager) by StefanoStem

JASON gives you a powerful JSON editor right in your browser sidebar - the coolest spot to paste your JSON snippets.

Save up to 20 named snippets across tabs with syntax highlighting, line numbers, and live validation.
Format to pretty print or minify to a single line in one click. Collapse and expand nested blocks instantly. Everything is saved locally, no network requests, no tracking, no data leaving your browser.

What's new in v1.1.0

Collapse All / Expand All nested blocks
Drag and drop to reorder tabs
Duplicate any tab in one click
Undo / redo up to 50 steps
Download snippets as JSON files
Real time file size indicator
Light and dark theme
Keyboard shortcuts for all main actions

Whether you're troubleshooting API payloads, inspecting partner requests, or just need a persistent place to manage your JSON.
JASON keeps everything organised and always within reach.