Convsta is a collection of 19 free, privacy-first developer tools that run entirely in your browser. No accounts, no data collection, no limits — just fast, reliable utilities for everyday development work.
Nothing you type or paste ever leaves your browser. Every tool runs entirely client-side in JavaScript.
No server round-trips means sub-millisecond results. Most tools work offline after the first page load.
Each tool does one thing extremely well. No unnecessary UI, no sign-up prompts, no dark patterns.
All core tools are and will remain free. We're supported by advertising, never by paywalls on basic features.
Convsta is built with vanilla HTML5, CSS3, and ES2022 JavaScript — no build steps, no frameworks, no transpilers. The project is intentionally kept dependency-light; where external libraries are used, they are loaded from jsDelivr CDN and chosen strictly for MIT or BSD licensing.
A few highlights of how specific tools are built:
The Regex Tester runs matching inside a Web Worker with a 2-second timeout to prevent browser hangs from ReDoS patterns. The SQL Formatter uses sql-formatter v15 with a custom left-to-right tokenizer for syntax highlighting. The cURL Client generates shell commands and optionally sends live requests directly from your browser using the Fetch API.
Have a bug report, a feature request, or a question? We'd love to hear from you.
The best way to reach us is by email. We review all messages and prioritize feedback from regular users when planning new tools.
Convsta is a free service supported by display advertising. Ads appear on the main page and around (not inside) tool interfaces, so they never interfere with your work. We participate in the Google AdSense program. Ad content is served by Google and is subject to Google's Privacy Policy.
If you use an ad blocker, Convsta still works fully — we never gate features behind ad views.