CourseexeDeveloper Ecosystem
About Courseexe

Built for Developers, By a Developer

Courseexe started as a personal project to solve a simple frustration — testing email delivery was too complicated, expensive, and privacy-invasive. It grew into a full ecosystem of free developer tools.

15+
Free Tools
100MB
Per User Storage
0
Ads or Trackers
100%
Open-Source Spirit
🎯

Our Mission

To build and maintain free, open-source developer tools that respect privacy, require no credit card, and work for every developer — whether you're a student side-hustling or a senior engineer debugging production. No paywalls, no ads, no trackers. Ever.

🌍

Why Open Source?

The developer community thrives on shared knowledge and open tools. Courseexe is built on open-source libraries and exists because of community support. Every donation goes directly to server hosting, SSL, database costs, and continued development — no VC money, no investors, just the community.

🔒

Privacy by Design

Every tool is designed to minimize data collection. Disposable inboxes are ephemeral. Tunnel traffic is never logged. Passwords and hashes are computed locally in your browser. We believe privacy is a right, not a feature.

💡

The Stack

Courseexe is built with Next.js, Go (Fiber), MongoDB, and deployed on a self-hosted VPS. The developer tunnel uses a custom TCP/TLS proxy. Everything is optimized for speed, low cost, and reliability — so we can keep it free for everyone.

What We've Built

15+ free tools and counting — all in one workspace

✉️
Disposable Mailbox
Instant throwaway email addresses with real-time SMTP delivery.
📧
SMTP Test Only
Validate SMTP server credentials and delivery flows online.
🎨
Email Template Generator
Drag-and-drop visual email builder with live HTML export.
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Email Header Analyzer
Full SPF, DKIM, DMARC verification with routing hop inspection.
Email Validator & MX Check
Verify syntax, MX records, and mailbox availability instantly.
🔑
Password Generator
Cryptographically strong passwords with entropy scoring.
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MD5 & SHA Hash Generator
Compute SHA-256 and MD5 signatures locally in your browser.
🎟️
JWT Debugger
Decode and inspect JSON Web Tokens without any network call.
🌐
URL Encoder / Decoder
Percent-encode or decode URL components for API debugging.
🆔
UUIDv4 Generator
Generate RFC-compliant UUIDs entirely in your browser.
Ping Latency Check
Real ICMP latency measurement to any public host.
📶
DNS Lookup
Resolve MX, A, CNAME, TXT, SPF, DKIM records for any domain.
🛡️
SSL Certificate Validator
Inspect TLS/SSL expiry, issuer chain, and cipher suites.
🗄️
Cloud Database Clusters
Instant isolated MongoDB clusters with full connection URI.
🔗
Developer Tunnel (HTTPS)
Expose localhost via a secure courseexe.com HTTPS subdomain.