Check a Used Charger Before You Buy New - and How to Spot a Fake
A used charger is almost always the better purchase. Clean it, buy from a real seller, then verify it with USB Connection Information. Genuine chargers report their true vendor and the correct PD profile ladder. Counterfeits rarely bother to hide either.
Read the guide →Why MagSafe Never Charges Your Mac Slowly (but USB-C Can)
Every Apple MagSafe 3 cable carries at least 5 amps, so the cable is never the bottleneck. USB-C cables aren't guaranteed that - which is why the same charger can be fast on MagSafe and slow on USB-C.
Read the guide →How Many Watts Does Your Mac Actually Need? (Only One Does 140W)
The 16-inch MacBook Pro is the only Mac that charges at 140W (EPR). Everything else caps at 100W, and the Airs pull about 70W. Buying past your Mac's ceiling does nothing.
Read the guide →The Best USB Tester Is Already in Your Computer - Mac, Windows or Linux
You don't need a physical USB tester. Mac, Windows, and Linux all expose the voltage, amperage, and PD contract already - the same data a $17 dongle shows, read straight from the OS.
Read the guide →The Wild West of USB Charging: How We Got From 2.5 Watts to Today
USB charging began at 2.5 watts, and going faster meant breaking the rules. The story of USB Battery Charging mode, the proprietary Wild West, and how Apple ended up crippling its own iconic charger to enforce the new standard.
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How to Check USB Status on Mac and Windows
Your computer knows the speed, power, and port of every USB device attached - it just doesn't show you. Here's how to read USB status on Mac and Windows.
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How I Test Chargers: The Watt Check Methodology
The complete test rig and methodology behind the Watt Check charger series - what's measured, what's controlled for, and why a USB 2.0 cable is the right call for power testing.
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USB-C Charging Speed and Data Speed Are Independent - Here's Why That Matters
Your 240W charging cable might only do USB 2.0 data. Your speedy USB 3.2 cable might cap at 60W charging. These specs are independent - here's why, and what to look for.
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Why Is My Device Connecting at USB 2.0 Speed? How to Diagnose a Slow USB-C Connection
A USB 3.x device stuck at 480 Mbps is almost always caused by a USB 2.0 cable. Here's how to confirm it and what to replace.
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Why Only Apple Chargers Show Their Name on Mac
Apple's chargers are the only USB-C chargers that fully identify themselves to macOS - name, model, firmware, serial. Here's why third-party chargers appear as generic 'Power Supply' and what the app shows in that case.
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Setapp vs Mac App Store: Where to get USB Connection Information
We're bringing USB Connection Information to Setapp's new Standalone store. Here is a breakdown of the differences between purchasing through the Mac App Store versus Setapp.
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Can You Charge a MacBook With an Old Apple iPad Charger? (Measured)
I tested an Apple 5W, 10W, and 12W USB-A brick against an M1 MacBook Air through a USB-C adapter. Spoiler: macOS falls back to USB BC 1.2 and caps at 7.5W regardless of the brick's rating.
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Why Are Some USB-C Cables Limited to 100W? EPR and USB PD 3.1 Explained
100W used to be the top of USB-C charging. USB PD 3.1 pushed the ceiling to 240W - but only with new EPR-rated cables. Here's why, and how to tell which ceiling your cable hits.
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USB-C Cable eMarker Chips: What They Are and How to Read One
The e-marker chip inside a USB-C cable decides whether you get 60W or 240W, and USB 2.0 or 40 Gbps. Here's what the chip actually declares, read off real cables, and how to check your own.
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Is My iPhone Connected via USB 2.0 or USB 3? How to Check
Your iPhone 15 Pro or 16 Pro supports 10 Gbps transfers - but the cable in the box is USB 2.0. Here's how to tell which speed you're actually getting, and the ~20× real-world difference.
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Thunderbolt 4 vs. USB4: Identifying Your Connection Type
Same plug, same marketing buzzwords - but Thunderbolt 4 and USB4 are not the same. Here's how to identify what you actually have.
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Why is my Mac Charging Slowly? Monitoring USB-C Power Delivery (PD)
Mac charging slowly? It's probably a Power Delivery negotiation mismatch. Here's how PD works and how to see the profiles your charger actually advertises.
Read the guide →How to Check USB-C Cable Speed & Data Transfer Rate
Identical-looking USB-C cables can run at 480 Mbps or 10 Gbps - here's how to verify the real negotiated speed on Mac and Windows.
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