I bought a “like new” laptop on an online marketplace once. The seller had five-star reviews. The photos looked great. The description said “barely used, works perfectly.”

The laptop arrived with a battery that lasted forty-five minutes, a keyboard with three dead keys, and a charging port so loose the cable fell out if you breathed near it. The seller had blocked me within an hour of delivery. I was out three hundred dollars.

I have bought plenty of used electronics since then and not been burned again. Here is what I learned from that three-hundred-dollar education.

The golden rules of buying used tech

1. Always test in person if possible. If you are buying locally, meet at a public place with Wi-Fi and power outlets. A coffee shop works. Boot the device, connect to Wi-Fi, open a few programs, check the battery health, test every port and key. Take your time. Anyone who rushes you is hiding something.
2. Ask for the serial number before you buy. Check it against manufacturer warranty lookup pages. On Apple devices, check the activation lock status — a device still locked to someone else’s Apple ID is a paperweight. On other brands, check if the device was reported stolen on sites like Swappa’s ESN check.
3. For shipped purchases, use a platform with buyer protection. eBay, Swappa, and Amazon Renewed all have policies that protect you if the item is not as described. Random marketplaces and social media listings do not. The extra ten percent you pay in platform fees is insurance.

What to check on specific devices

Phones: check the battery health percentage (iPhone: Settings → Battery → Battery Health. Android: use an app like AccuBattery). Below eighty percent and you will need a replacement soon — factor that into the price. Also check for screen burn-in by opening a solid white image. Look for ghosted icons or uneven tint.

Laptops: run a battery report (Windows: powercfg /batteryreport. Mac: System Information → Power → Cycle Count). Check the physical condition of the charging port — wiggle the cable gently. A loose port is a common failure point and an expensive repair.

Cameras and lenses: ask for the shutter count. Entry-level DSLRs are rated for about 100,000 actuations. Pro bodies go to 200,000 or more. Take a photo of a blank wall or sky at the smallest aperture and zoom in — look for sensor dust spots. Check for fungus in lenses by shining a flashlight through the glass. Fungus looks like tiny spider webs and cannot be cleaned.

When used is worth it and when it is not

Worth buying used: phones one or two generations old, laptops from premium brands (ThinkPad, MacBook), cameras and lenses, game consoles, monitors. These items have long lifespans and clear depreciation curves.

Better to buy new: hard drives and SSDs (you have no idea how many hours are on them), headphones (hygiene), and anything with a non-replaceable battery that is more than three years old.