Hey Product Hunt 👋 I built Stax because I got tired of the same broken pattern: open a free online tool → hit a paywall after 3 uses → forced signup → "your file size exceeds the free limit" → email confirmation → upgrade prompt. Just to format some JSON. Or compress a PDF. Or calculate an EMI. Stax is 235 free tools across 15 categories — developer, finance, PDF, image, health, civil engineering, electronics, and more. Three rules I refused to break: No login. Ever. Not even for "premium" features. There are none. No tracking. Your files never leave your browser. Open DevTools and check the Network tab — nothing uploads. No limits. No file size caps, no usage quotas, no daily limits. Some tools I'm most proud of: JSON Formatter (handles 50MB+ files locally) PDF Compressor (truly browser-based, no server upload) EMI / SIP / GST Calculators (India-focused, but useful globally) Civil Engineering calculators (rare to find free) I'd love to hear: which free online tool has annoyed you most with logins/paywalls? I'll try to add it to Stax this month. – Harshil

Stax Tools

Free online tools for developers, finance, AI writing, PDFs

Free online tools for developers, finance, AI writing, PDFs