JSON Viewer: Open JSON Files

Open any JSON file on your phone — even a 100 MB one — and actually read it.

JSON Viewer is a fast, offline JSON, JSONL and NDJSON file viewer, formatter and tree reader for Android. Built for developers who need to read API responses, log dumps and config files away from their desk.

OPENS FILES THAT OTHER APPS CHOKE ON
- JSON documents up to 100 MB and trees with 10,000+ nodes
- Virtualized rendering: scrolling stays smooth no matter how deep the structure
- Indexed search, so finding a key in a huge payload is instant

FORMATS
- .json — standard JSON files
- .jsonl / .ndjson — line-delimited JSON opened as one browsable array
- Per-line error reporting tells you exactly which line is broken instead of rejecting the whole file

BUILT FOR INSPECTION
- Tap any value for a detail sheet with type, length, byte size and full JSONPath
- Copy the value or the path with one tap
- Expand or collapse single nodes, or Expand all / Collapse all
- Type-aware colors and icons for strings, numbers, booleans, nulls, objects and arrays

SEARCH THAT HELPS
- Case-insensitive search across keys and values
- Matches are highlighted in place and parent nodes auto-expand so you see results in context
- Live match counter

MADE FOR THE WAY DEVELOPERS WORK
- Recent files: your last 10 documents, one tap away, with sizes and timestamps
- Light and dark themes that follow your system setting
- Haptic feedback on the interactions that matter
- Full screen reader and accessibility support

PRIVATE BY DEFAULT
- Everything happens on your device. No account, no upload, no cloud
- Works fully offline

TYPICAL USES
Debugging an API response on the train. Pretty printing a minified payload. Validating a config file before you deploy. Reading a JSONL log your backend wrote. Opening a .json export that no other file viewer on your phone will touch.

JSON Viewer shows a single banner ad to fund development. No subscriptions, no paywalls, no sign-up.