JsonLab
A developer's utility belt — JSON tools with tree view & structural diff, UTF-8 safe Base64, URL encoder & parser, and a live regex tester. Everything in your browser. No upload.
Input
Root type—
Depth—
Objects—
Arrays—
Keys—
Leaves—
Strings—
Numbers—
Left (original)
Right (modified)
0 added
0 removed
0 changed
0 total path changes
Plain text
Base64
Both fields are live and bidirectional: typing in one updates the other. The text field is UTF-8 aware,
so emoji and non-ASCII characters round-trip correctly (unlike a naive btoa).
Plain text or URL
Encoded
URL components
Query parameters
Test string
Replace
Match details
The EuKosmos family
Local-first tools for researchers, writers, and developers. Everything in your browser. Nothing uploaded.