Free online tools for devs in one place
JSON, UUID, Base64, Regex, QR Code, text, dates, colors, QA workflows and automation
Tools for developer productivity
4DevTool centralizes free browser-based tools for developers, students, QA teams and product teams. Use JSON Formatter, Base64, JWT Decoder, Regex Tester, QR Code, UUID, text utilities, date tools, colors, calculators, cron builder, cURL helpers and more without creating an account.
The site is built for practical software work: formatting payloads, testing validation rules, preparing demos, generating non-production test values, checking API data and speeding up everyday development workflows in the browser.
4DevTool also provides country-focused synthetic data pages for Brazil, the United States and other regions, with localized generators and validators for common formats, addresses, names, companies and regional identifiers used in development and QA workflows.