Developer tools
Small deterministic utilities for development work.
Free developer tools for JSON formatting and validation, regex testing, Base64, URL encoding and decoding, and multilingual cron schedules — all designed to run in the browser.
Browse the collection
Developer Tools
Cron Expression
Write a common schedule in EN, IT, ES, FR, DE or PT and get validated cron for Unix, GitHub Actions or Cloudflare.
Base64 Encoder / Decoder
Encode or decode UTF-8 text as Base64 locally with strict validation.
URL Encoder / Decoder
Encode and decode URI or URI-component text without sending it anywhere.
JSON Formatter
Validate, pretty-print and minify JSON locally in your browser.
Regex Tester
Test JavaScript regular expressions locally and inspect matches, indexes and capture groups.
About this collection
Choose the tool for the job.
Developer tools focus on narrow, repeatable tasks with clear outputs and no account requirement. Format or validate structured data, test expressions, transform encoded text, or inspect schedules without sending your input to a remote processing service.
JSON Formatter validates, pretty-prints and minifies JSON; Regex Tester shows JavaScript matches and capture groups; Base64 and URL tools encode or decode text locally; Cron Expression generates, validates and previews five-field schedules in multiple languages.
← Browse all Sikelia Tools