ElDevo

ElDevo toolkit

Developer Tools

Search, filter and save browser-based tools for JSON, JWT, Cron, encoding, SQL, URLs, text and more.

20 tools

Ctrl/Cmd + K opens global search
Encoding

Base64 Encoder / Decoder

UTF-8 safe Base64 encoding and decoding with optional URL-safe alphabet. Everything happens locally.

Utilities

Cron Expression Generator

Build cron schedules interactively, translate them to plain English and preview the next five run times locally.

Converters

CSV to JSON Converter

Parse CSV or TSV data with Papa Parse and export a clean JSON array locally.

Security

Hash Generator

Calculate SHA-1, SHA-256, SHA-384 and SHA-512 hashes with the browser Web Crypto API.

Encoding

HTML Entity Encoder / Decoder

Encode special characters such as &, < and > into HTML entities, or decode entities back to readable text.

Web

HTML Formatter

Beautify HTML documents locally with readable indentation and browser-native parsing.

JSON

JSON Formatter & Validator

Fast browser-based JSON formatter and validator with precise syntax errors. Your JSON never leaves this device.

JSON

JSON Path Tester

Explore JSON data with a lightweight client-side JSONPath-style query tool supporting dot paths and array indexes.

JSON

JSON Schema Validator

Validate a JSON document against a practical subset of JSON Schema locally, including types, required properties, arrays and enums.

Converters

JSON to TypeScript Converter

Turn JSON examples into readable TypeScript interfaces locally, including nested objects and arrays.

Converters

JSON to YAML Converter

Convert JSON to readable YAML using js-yaml entirely in your browser.

Security

JWT Decoder

Decode JSON Web Tokens entirely in your browser. Inspect header, payload, expiration and signature status without verification or server uploads.

Utilities

Number Base Converter

Convert integer values between common number bases with validation and optional prefixes.

Utilities

Regex Tester

Test JavaScript regex patterns live, inspect matches and capture groups, and get safe syntax errors without sending text to a server.

SQL

SQL Formatter

Pretty-print SQL with selectable dialects, consistent keyword casing and instant local formatting.

Utilities

Text Case Converter

Transform text into uppercase, lowercase, Title Case, camelCase, PascalCase, snake_case and kebab-case.

Utilities

Unix Timestamp Converter

Convert Unix seconds or milliseconds to readable dates and convert ISO/local dates back to Unix timestamps.

Web

URL Parser & Encoder

Parse URLs into protocol, host, path, query and hash components, or encode/decode URL text in your browser.

Utilities

UUID Generator

Generate one or many UUID v4 identifiers using the browser's crypto.randomUUID API when available.

Converters

YAML to JSON Converter

Parse YAML locally with js-yaml and generate strict, readable JSON without uploads.