About Utilko
Utilko is a collection of 300+ free online tools across 13 categories, built on one simple principle: tools should be fast, private, and free — no account, no data sent to servers, no upsell.
Why Utilko exists
The "free online tool" space is mostly a trap. Search for "JSON formatter" and most results will: require a signup to save, run the entire tool server-side (logging your data), inject ads between you and the tool, limit usage to push you toward a paid plan, or disappear when the free tier gets rate-limited.
Utilko is the opposite of that model. Every tool here runs locally in your browser using standard web APIs — JavaScript, WebAssembly, the Canvas and Crypto APIs — with no round trip to a server. You could disconnect your internet mid-use and most tools would keep working.
How we keep tools free
Utilko is ad-supported. We show unobtrusive ads on page; we never gate tools or inject ads into the tool UI itself. We also link to PDFEdits (a sister site with 88+ advanced PDF tools) for heavier PDF workflows.
There is no paid tier. There will never be. The catalog is updated as tools are identified — we prioritize tools that solve a specific task cleanly over general-purpose alternatives.
Privacy & data handling
The default answer to "does Utilko see my data?" is no. Here's the long version:
- Client-side tools: Everything you paste, upload, or type into a tool stays in your browser. JSON you format, passwords you generate, images you compress, text you hash — none of it reaches our servers.
- Verification: Open your browser's DevTools → Network tab, use a tool, and you'll see no requests fire for the actual work. (You can verify this on any tool page.)
- Ads: Ad networks may set cookies and track impressions per standard ad-tech practice. This is the one place user data is handled by third parties; it's disclosed in the footer ad placements.
- Analytics: Basic aggregate traffic is logged via Cloudflare. No personal identifiers are collected.
- Server-side exceptions: A handful of tools (public API, IP lookup) necessarily contact an external service to function. These are clearly labeled.
What Utilko is built with
Utilko runs on Astro with React islands for interactive tools, styled with Tailwind CSS, deployed to Cloudflare Pages for edge performance. Pages are pre-rendered static HTML with minimal JavaScript hydration — most tool pages measure under 600ms LCP and 0.00 CLS.
The full tool catalog is available as a free public JSON API at utilko.com/api/tools. Every tool also has an embeddable <iframe> and a widget script so you can drop Utilko tools onto your own site.
Accuracy & corrections
Comparison and how-to pages reflect current best practices as of the publication date shown in the schema. Cryptographic tools (password generation, hashing, UUID) use the browser's built-in crypto.getRandomValues() API, which is cryptographically secure. Math calculators use standard formulas linked from the tool's FAQ section. If you spot a factual error or outdated recommendation, we update content based on reader feedback.
Contact & links
- Full tool catalog: utilko.com/all-tools
- How-to guides: utilko.com/how-to
- Comparisons: utilko.com/compare
- Cheat sheets: utilko.com/cheat-sheets
- Free API: utilko.com/api-docs