I built a free Email Authentication Checker that runs entirely in your browser

Rebin M — Thu, 23 Apr 2026 09:03:10 +0000

I kept using 3 different sites just to check SPF, DKIM, and DMARC for a single domain. It was slow, most of them are covered in ads, and I was never sure what data they were keeping.
So I built one tool that checks all three at once using DNS-over-HTTPS via Cloudflare's public resolver. Nothing goes to any server I control. You paste a domain, it returns the raw records and a plain-English explanation of what each one means.
It also tells you if something is missing and what a basic fix looks like.
Link: it-toolskit.org/tools/email-auth-checker
I have 21 other free tools on the same site — subnet calculator, security headers analyzer, robots.txt tester, JSON formatter, and more. All run in the browser, no signup, no tracking.
Built the whole thing as a static site on Cloudflare Pages. Happy to answer questions about how any of the tools work technically.

I Built a Simple Toolkit to Make Everyday Developer Tasks Faster

Rebin M — Tue, 14 Apr 2026 07:08:49 +0000

I kept losing time on small things during development.

Not complex problems — just repetitive tasks like formatting data, cleaning text, or doing quick conversions.

Individually they take seconds, but they constantly break your flow.

Most tools I tried felt too heavy for this — too many steps for something simple.

So I built a small toolkit for myself.

Just simple utilities that:

open instantly
do one job
give results immediately

No accounts, no setup.

I’ve been using it daily at work, and a few people I shared it with started using it too.

If you deal with similar small tasks, this might be useful:

👉 Try it here: https://it-toolskit.org

Curious — what’s one small task you keep repeating during development?

DEV Community: Rebin M

I built a free Email Authentication Checker that runs entirely in your browser

I Built a Simple Toolkit to Make Everyday Developer Tasks Faster