OnSumo Tools

DevTools

Private browser-side helpers for day to day dev tasks.

Private JSON Validator & Formatter

Validate and format JSON in-browser with line and column hints, key sorting, and copy or download output.

Regex Visualizer & Tester

Test JavaScript regex with full match indexes, group captures, runtime stats, and replacement preview.

Visual Cron Schedule Builder

Build cron expressions visually with presets, field editor, plain English summary, and next ten run times.

JWT Decoder & Debugger

Decode JWT header and payload in-browser with expiry badges, claim notes, and optional HMAC signature checks.

JSON to TypeScript Interface Generator

Paste JSON to generate TypeScript interfaces, type aliases, or Zod schemas with nested types and optional fields.

SQL Formatter (Multi-dialect)

Format SQL with indentation, keyword casing, and dialect-aware quoting for MySQL, PostgreSQL, BigQuery, and T-SQL.

Markdown Live Editor

Write Markdown with live HTML preview, GFM tables and task lists, sync scroll, and export to HTML or .md.

JSON Diff Viewer

Compare two JSON objects with color-coded added, removed, and changed keys plus a copyable diff report.

Base64 encoder / decoder

Encode and decode Base64 with standard, URL-safe, MIME, UTF-8, file upload, and image preview.

URL encoder / decoder

Percent-encode and decode URLs, query strings, and path segments with RFC 3986 or form rules.

UUID generator

Bulk UUID v4, v5, and nil generator with uppercase, hyphen, SQL format, validation, and download.

Hash generator

MD5 and SHA family hashes plus HMAC for text or files with hex, Base64 output, and hash compare.

JSON to YAML converter

Bidirectional JSON and YAML conversion with validation, indent options, and anchor resolution.

HTTP status codes

Searchable HTTP status reference with causes, fix guidance, class filters, and RFC notes.