The Core Difference
MXToolbox and PortJar overlap on email and DNS tooling — both do SPF, DMARC, MX record lookups, and blacklist checks. But they diverge sharply in scope and depth. MXToolbox goes deep on email deliverability with monitoring, alerts, and detailed diagnostic reports. PortJar goes wide — 29 tools covering networking, connectivity, TLS, and utilities that MXToolbox doesn't touch.
The choice is about what you're optimising for: email deliverability depth (MXToolbox) or network engineering breadth (PortJar).
DNS & Email Tools
MXToolbox wins on email-specific depth — its blacklist checker covers 100+ lists, its email header analyser is more detailed, and its monitoring and alerting features are genuinely useful for deliverability teams. PortJar covers the same ground at a shallower depth, sufficient for quick checks but not for ongoing monitoring.
Network & Connectivity Tools
PortJar wins here — port checking, TLS/SSL inspection, CIDR calculator, IP geolocation, BGP/ASN lookup, and traceroute are either absent from MXToolbox or buried in paid tiers. For network engineers who need more than email tooling, PortJar is the broader toolkit.
Utilities
PortJar covers hash generators, Base64 encoders, regex testers, and URL encoders — client-side tools that run entirely in the browser. MXToolbox has no equivalent. For developers who need quick encoding or hashing alongside network checks, PortJar saves another tab.
Pricing
| Tool |
Free Tier |
Paid |
| PortJar |
All 29 tools free. Client-side unlimited. Server-side rate-limited after 10. |
No paid tier |
| MXToolbox |
Basic lookups free. Monitoring and alerts require paid plan. |
From $129/mo (Pro) |
Verdict
Use MXToolbox if email deliverability is your primary concern — its depth on blacklist monitoring, header analysis, and alerting is unmatched at any price point. Use PortJar if you need a free, fast, consolidated toolkit for general network engineering — DNS, port, TLS, CIDR, and utilities in one tab with no signup. For most developers and sysadmins, PortJar covers 80% of daily network checks for free. MXToolbox is the specialist you call when email deliverability becomes a dedicated workstream.