Park Street Post Software

WireRate

Two Macs, one cable.
A straight answer.

You ran the cable, plugged in both ends, and the light came on. That says nothing about whether it carries full speed. Open WireRate on both Macs and press Test. About a minute later you know the speed the link came up at, the speed it really carries in each direction and in both at once, and whether any packets went missing on the way.

$7 once. No subscription, no account, and no internet connection required. Only the Mac you test from needs a license: the Mac at the other end runs WireRate free, forever. Try every feature for 7 days first, and if it is not for you there is a no-hassle 14-day refund policy.

/01 One button About a minute · no setup

Connect the two Macs with the cable you want to check, directly or through wall jacks and a patch panel. Open WireRate on both. They find each other over that cable on their own: no IP addresses, no server to start, nothing to configure, and Wi-Fi stays on. Press Test.

WireRate runs four checks back to back and lights each one as it finishes. Then it tells you what they add up to, in a sentence.

WireRate after a test between two MacBook Pros: four green lights reading Outbound 928 Mbps, Inbound 929 Mbps, Duplex 925 / 925 and Quality No loss, a 1 Gbps link between the two Macs, and the line Gigabit-class speed both ways. No packet loss.
A finished test on a direct gigabit cable: 928 Mbps out, 929 in, 925 each way with both directions running at once, and not one lost packet. Each adapter's top speed sits above its Mac; the speed the link actually came up at runs between them.
  • SetupNone
  • TestAbout a minute
  • PathEthernet only
  • ResultIn plain words
/02 Four checks Outbound · Inbound · Duplex · Quality
  • Outbound and inbound Sustained throughput one way at a time: a warm-up, then ten measured seconds, counted by the Mac on the receiving end. On a healthy gigabit link that is about 930 Mbps, close to the most a gigabit link can carry once Ethernet and TCP take their share.
  • Duplex Both directions at full speed at the same moment. Ethernet is built to carry both at once, so a healthy link holds its speed here too. When one direction sags, WireRate shows which one, and whether any data had to be resent along the way.
  • Quality A packet check in each direction that counts every packet that went missing or arrived late. If the receiving Mac rather than the cable could not keep up, WireRate retries that direction at a lower rate and tells you which it was.
  • Link and adapters The speed the link negotiated, recorded on both Macs before and during the test, next to what each adapter supports. Two gigabit adapters that came up at 100 Mbps is the classic sign of a damaged pair, and WireRate says so in as many words.
WireRate during the duplex stage: blue arrows flowing out and magenta arrows flowing in along the cable at the same time, 925 Mbps each way, with Outbound and Inbound already lit green.
The duplex stage, mid-test: traffic in both directions at once, each side measured live. The two one-way stages before it have already passed.
WireRate during the packet check: a line of blue dots crossing the cable, with Outbound, Inbound and Duplex lit green and Quality in progress.
The packet check runs last. Every packet is numbered, so a gap is counted exactly instead of estimated.
/03 Answers, not graphs What a result tells you

A speed graph leaves the diagnosis to you. WireRate reads its own measurements and says what they point to, in one line in the window and in full in the report.

  • A healthy link says so: gigabit-class speed both ways, no packet loss.
  • A link that negotiated below what both adapters support is called out, with the advice to check the cable.
  • Uneven directions name the slower one and give both numbers.
  • A drop with both directions running says whether data had to be resent. A clean, flat limit with no resends points at a Mac rather than the cable, and WireRate says that too.
  • Lost packets are counted and reported as a count, out of how many were sent.
  • An adapter plugged into a USB 2 port, which caps it near 300 Mbps, is named instead of the cable.
  • Low Power Mode on a laptop can hold back its speed, so WireRate asks before testing on a Mac that has it on, and names it if the result came out slow.
/04 One license covers the pair Remote Mode is free

Only the Mac that starts a test needs a license. Put the same free download on the other Mac and it runs in Remote Mode: it takes part in every test, shows the results as they arrive, and never expires.

So the Mac at the far end of the building, a client's machine or a colleague's laptop never needs a purchase of its own.

WireRate on the second Mac, titled Remote Mode, showing the same finished test from its side: 929 Mbps out, 928 in, no packet loss, and a link reading Use this Mac to start tests.
The other end of the same test, in Remote Mode. It sees everything; starting a test is the one thing it leaves to the licensed Mac.
/05 The full report Details · Copy Report

Behind every result is a report with the working shown: each stage second by second, data resent, packet-check counts, both Macs' adapters and link readings, and the interface error counters before and after.

Copy it in one click and send it to whoever looks after the network. The plain-language summary sits at the top; the numbers that back it follow.

WireRate's Connection Details window: the assessment reads Connection looks healthy in this quick test, Gigabit-class performance, with the build, connection and adapter sections below.
The top of the Details report for the test above. Every claim in the summary is backed by the measurements further down.
/06 Honest about what it measures Observation, not certification
  • A tester, not a certifier WireRate measures how this cable performs between these two Macs, today. It cannot tell you a cable's category, its length, or its crosstalk and return-loss figures. Those take a dedicated certifier, which costs thousands.
  • Ethernet, and only Ethernet Every test is pinned to the wired adapter and checked while it runs. If the traffic would move to Wi-Fi or anywhere else, the test stops rather than quietly measuring the wrong thing.
  • Never a background load Every test ends on its own within about two minutes. A Mac accepts one only while WireRate is open on a direct wired path, so it never becomes a traffic generator on a shared network.
  • Private No account and no telemetry. Measurements travel between the two Macs on the cable and nowhere else. They never reach us.
  • Works offline The app and its license work without an internet connection, forever. The cable under test is the only network it uses.
  • No admin rights Nothing to install beyond the app. It changes no network settings, needs no password, and runs inside the macOS app sandbox.
/07 What you need Two Macs · Ethernet on each

Two Macs running macOS 15 or later, an Ethernet connection on each, and the cable between them. The free download shows whether it can use your adapter before you buy anything.

  • Built-in Ethernet on Mac mini, Mac Studio, iMac and Mac Pro, and Thunderbolt Ethernet adapters and docks.
  • USB Ethernet adapters built on the Realtek RTL8153 or ASIX AX88179 chips, the chips inside many USB-C gigabit adapters. USB adapters for 2.5 Gbps and faster are not supported yet.
  • The cable can run straight between the Macs or through wall jacks and patch panels. Tests run only over a direct path with no router in it.
  • Tested so far with USB gigabit adapters between Apple silicon Macs, on gigabit and 100 Mbps links. Built-in and Thunderbolt Ethernet, faster links (2.5, 5 and 10 Gbps) and Intel Macs get the same measurements but have not been tested on hardware yet.
/08 Questions you would actually ask Straight answers
Do I need to buy it twice?
No. Install it on both Macs; only the one you start tests from needs a license. The other runs in Remote Mode, free, with no time limit.
Can it test the cable inside my wall?
Yes. Plug each Mac into a wall jack at either end of the run. The result covers the whole path between the two Macs: patch cords, jacks, the run itself and the adapters.
Will it tell me whether my cable is Cat 6?
No. It tells you how fast and how cleanly the cable carries data between two Macs, which is usually the question behind that one. Category, length and crosstalk measurements need a cable certifier.
Does it work over Wi-Fi, or across the office network?
No, on purpose. WireRate tests the wired path between two Macs, and only a direct one with no router in it. Leave Wi-Fi on; WireRate keeps its traffic on the cable.
My result came out slow. Is the cable bad?
Maybe, and WireRate tries to tell you. A link that came up below what both adapters support usually is the cable. A slow result with no resent data, a Mac in Low Power Mode, or an adapter on a USB 2 port points elsewhere, and the result says which.
How does the trial work?
When you choose Start 7-Day Trial in the app, every feature is on for 7 days. If you never start it, the app simply runs in Remote Mode, which is what the Mac at the far end of the cable usually wants anyway.
How does the license work?
You get a small signed file by email. Double-click it, or choose Enter License from the WireRate menu, the one next to the Apple menu. It works offline forever, on the Macs you personally use.
Something is wrong, who do I ask?
The person who built it answers: support@parkstreetpostsoftware.com.