Test JavaScript template literals live — ${} interpolation, nesting, and escaping, evaluated instantly with instant error highlighting. Code never leaves your device — formatting and validation run locally in your browser.
Content reviewed October 2026 · About Toolzum
Provides an interactive environment where users can write a regular expression pattern, test it against sample strings, and view real-time match. Code never leaves your device — formatting and validation run locally in your browser.
Test any HTTP endpoint by sending GET, POST, PUT, or DELETE requests directly from your browser. View response status, headers, and body.
Test GraphQL queries with variables. Format queries and variables, and preview formatted responses for development and debugging.
Queue RAW files (CR2, NEF, ARW, DNG, RAF, ORF, RW2, PEF, SRW) — each gets a live browser decode test with a green/red dot; supported ones convert to JPG, PNG, or WebP at quality 10–100% (default 92, hidden for PNG), one by one or all at once. Canvas re-encoding drops metadata — local processing, unlimited saves.
Compute test percentages and grades from correct/total with curve options. Turn 42/50 into 84% (B) instantly — free, local, no signup.
JavaScript template literals — ${} interpolation, nesting, and escaping, evaluated live.
Instantly, with the failing expression highlighted in the editor.
Yes — backtick blocks evaluate with newlines intact, exactly like runtime.
No — evaluation runs locally in your browser, free with no signup.
String Inspector
Inspect any string — view character count, byte length, word count, line count, Unicode code points, and non-ASCII character breakdown.
JSON Formatter
Pretty-prints raw JSON with configurable indent width, key sorting, and bracket collapsing options while flagging syntax errors with exact.