About DogTools
DogTools is a focused collection of free online tools for developers, frontend engineers, system administrators, network engineers and technical SEO practitioners. Instead of another junkyard of generic converters, we build the small, sharp utilities engineers actually reach for while debugging: an HTTP header analyzer, a JWT parser and signature validator, a regex explainer, a CIDR subnet calculator, a MIME type lookup, a batch Base64 encoder, and a WCAG contrast checker.
Our principles
- Local-first. Every calculation runs in your browser with JavaScript. The text you paste — headers, tokens, IP addresses, passwords-adjacent secrets — is never transmitted to a server.
- No friction. No sign-up, no login wall, no email gate, no usage limits. Open a tool and work.
- Documentation, not just widgets. Every tool page explains the underlying concept, shows real use cases and answers common questions, so you leave knowing more than you arrived.
- Fast and static. The site is statically generated and served from the edge; tool code loads on demand. It scores well on Core Web Vitals and works on mobile.
- Honest and maintainable. We avoid file-upload tools, media conversion and anything that would require storing or processing your data on a server.
Who runs this site?
DogTools is an independent project built by developers for developers. It is funded by lightweight advertising and planned optional Pro features (such as exportable reports), with the core tools remaining free forever. We do not sell user data — there is no user data to sell.
Contact
Found a bug, want a new tool, or noticed an outdated fact in an article? Reach us at jialixun88@gmail.com. We read everything.