port vs MXToolbox
Both help you understand ports — but in completely different ways. port is a searchable reference library: type a port number or service name and get the protocol, purpose, and common usage across 500+ dev ports. MXToolbox is a live diagnostics suite that actually connects to a host and tests whether a given port is open, plus email health, DNS, and blacklists.
port
- Searchable library of 500+ common dev ports
- Search by port number or service name
- Protocol (TCP/UDP), standard service, and usage description per port
- Instant — no network connections, no waiting
- Runs entirely in browser, zero dependencies
- No account, no ads, free forever
MXToolbox
- Live open-port tester — actually connects to a host
- Email infrastructure checks: SPF, DKIM, DMARC, MX records
- Blacklist monitoring across 100+ RBLs
- DNS lookup, SMTP diagnostics, website diagnostics
- Some features require account registration
- Free tier available with ad-supported interface
Feature comparison
| Feature | port | MXToolbox |
|---|---|---|
| Port number reference (what service runs here) | ✓ 500+ ports with descriptions | — no reference database |
| Live open-port connectivity test | — reference only, no live test | ✓ connects to target host |
| Search by service name | ✓ e.g. "redis", "postgres", "smtp" | — |
| Email health checks | — | ✓ SPF, DKIM, DMARC, MX, SMTP |
| Blacklist check | — | ✓ 100+ RBLs |
| DNS lookup | — | ✓ MX, A, CNAME, TXT |
| Protocol (TCP/UDP) noted per port | ✓ | — |
| No account needed | ✓ | partial — some features need account |
| No ads | ✓ | — ad-supported |
| Works offline / no network calls | ✓ | — requires live connection |
| Best for | identifying unknown ports, protocol lookup | live connectivity testing, email diagnostics |
Frequently asked questions
What is the difference between port and MXToolbox?
port is a searchable reference library for common developer ports — type a port number or service name and get the protocol, standard usage, and what typically runs there. It does not make live network connections. MXToolbox is a live diagnostics tool that actually tests whether a port is open on a remote host, and also checks email reputation, SPF/DKIM/DMARC, blacklists, and DNS health. Use port to look up what a port is; use MXToolbox to test whether that port is reachable.
Can port check if a port is open?
No. port is a reference library and does not make live network connections or scan remote hosts. It tells you what service normally runs on a given port number. MXToolbox's open port checker actually connects to a host and reports whether the port accepts connections.
What ports does the port tool cover?
port covers 500+ common dev ports including HTTP/HTTPS (80, 443), SSH (22), databases (3306 MySQL, 5432 PostgreSQL, 27017 MongoDB), caches (6379 Redis, 11211 Memcached), mail (25, 587, 993, 995), DNS (53), and many more. Search by port number or service name.
Does MXToolbox have a port number reference?
No. MXToolbox's port checker asks you for a host and port number to test, but does not provide a lookup table explaining what services use which ports. port fills that gap — it is the reference layer before you test live connectivity.
When should I use MXToolbox instead of port?
Use MXToolbox when you need to test whether a specific port is actually open and reachable on a remote host, or when you need email infrastructure health checks — SPF, DKIM, DMARC, MX records, blacklist status. Use port when you want to know what service runs on a given port number, identify an unknown port, or look up the protocol without making any live connections.
Is port a MXToolbox alternative?
They serve different workflows. port is a reference tool for identifying and understanding port numbers — instant, offline-capable, no network calls. MXToolbox is a live diagnostic suite. Most developers use both: port to understand what a port should be running, then MXToolbox or portchecker.co to verify it is actually open and reachable.
Try port now
Searchable library of 500+ common dev ports. Protocol, purpose, usage — no live connections, instant results.
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