Code & Dev Tools
Free Online Code & Dev Tools
Code utilities for developers that run entirely in your browser. Format and minify code, test regex patterns, generate UUIDs, encode Base64, build cron schedules, and compare semver strings — with no data sent to any server.
Why code tools should run in the browser
Server-based code tools introduce unnecessary risk — JWT tokens, database passwords, sensitive SQL queries, and API keys are transmitted to a third-party server every time you paste them into an online tool. Browser-based tools eliminate this entirely: your code stays in your browser tab.
Every tool on this page uses only browser-native APIs and pure JavaScript logic. JSON.parse() for formatting, native RegExp for regex testing, crypto.randomUUID() for UUIDs, TextEncoder for Base64. No server, no network requests, no external dependencies.
Performance is better too — client-side tools respond instantly with no round-trip latency. Large JSON files, complex SQL queries, and thousand-line CSS stylesheets all process at native speed.
Code & Dev best practices
FAQ
Common questions
Is it safe to paste API keys or JWT tokens into these tools?
Yes — these tools run entirely in your browser. Your input is never transmitted anywhere. Verify by opening DevTools → Network tab and confirming zero network requests while using the tools.
What is the difference between Base64 and URL encoding?
Base64 converts binary data to ASCII text using 64 printable characters. URL encoding converts special characters to percent-encoded sequences safe for URLs. They serve different purposes and are not interchangeable.
When should I use UUID v4 vs UUID v1?
UUID v4 is randomly generated — use it for database primary keys, session tokens, and idempotency keys. UUID v1 embeds a MAC address and timestamp — useful when sortability matters, but reveals machine identity.
What SQL dialects does the formatter support?
The SQL formatter handles standard SQL including MySQL, PostgreSQL, SQLite, and SQL Server. It targets ANSI SQL as the baseline — dialect-specific syntax may not be perfectly formatted but will be valid output.
What cron syntax platforms are supported?
The cron generator supports Unix/Linux (5 fields), Quartz/Spring (6–7 fields), AWS EventBridge, GitHub Actions, and Kubernetes CronJobs. Each platform has slightly different rules — select your platform to see the correct syntax.