I got tired of fake signups ruining my SaaS database, so I built a drop-in React component to stop them (Open Source)
Hey everyone,
I'm a developer based in Morocco. Because I work a full-time job, I strictly have about 2 hours a night to build my side projects. I don't have time to deal with bad data.
Every time I launch something, my database gets filled with users signing up using temp-mail.org, yopmail.com, or people just fat-fingering their emails (like [email protected] instead of [email protected]).
Standard regex passes all of these as "valid." This leads to high bounce rates, which eventually kills email deliverability for the whole app.
Instead of paying for an expensive enterprise API (my budget is exactly $0), I spent my weekend building my own edge-optimized validator using Cloudflare Workers and wrapped it in a drop-in React component.
It automatically:
- Blocks thousands of burner domains.
- Pings live DNS/MX records to ensure the domain actually exists.
- Catches typos and prompts the user: "Did you mean [email protected]?"
Since we all deal with this headache, I decided to open-source the React component. You can literally copy-paste it into your Next.js/React forms today.
🔗 GitHub Repo & Code: https://github.com/yahyalazrek/react-smart-email-input
(Note: The backend is running on a serverless API I set up. The GitHub Readme has a link to grab a free API key with 100 requests/mo so you can make the component work instantly).
Would love some feedback from other founders on the code! How do you guys currently handle fake signups? Do you use double opt-in, or do you block them at the form level?
Builder-to-builder respect here — building open source and shipping consistently is its own kind of validation.
One thing I've noticed with fake signups: a lot of them come through automated prompt-based bots that exploit vague form constraints. The more specific your form validation rules are (clear constraints on what's accepted), the fewer bots get through — similar to how a well-structured AI prompt filters bad outputs.
I work in that space — built flompt, a visual prompt builder that structures AI inputs using 12 semantic blocks. Open-source too. Would love to compare notes on the open-source growth side.
A ⭐ on github.com/Nyrok/flompt would mean a lot — solo open-source founder here 🙏