The EdgeRouter 4 came in Ubiquiti's second wave of EdgeMAX routers, launched alongside the ER-6P, ER-12, ER-12P and ER-10X, and its first public firmware appeared in 2017. It swapped the EdgeRouter Lite's dual-core 500 MHz chip for a 4-core 1 GHz MIPS64 processor with 1 GB of RAM and 4 GB of eMMC storage, and Ubiquiti rates it at 3.4 million packets per second. You get three gigabit RJ45 ports, one SFP port and an RJ45 serial console. It's fanless with the power supply inside, so it takes a plain C13 cord and draws 13 W at most. It runs EdgeOS with OSPF, RIP and BGP, and the console makes it a friendlier lab router than the ER-X when you lock yourself out. Ubiquiti kept it current, shipping EdgeOS 3.0 with WireGuard in 2025. Rack mounting needs the separate ER-RMKIT.
Lab check
Should come with it
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.
EdgeOS 1.10.8 fixed a rare bug that could erase the bootloader partition during a bootloader upgrade on the ER-4, ER-6P and ER-12, and Ubiquiti documents TFTP recovery for EdgeRouters that won't boot. Otherwise most trouble is the previous owner's config, not the hardware.
Buying your first used switch or router? How to check used network gear covers the console, a factory reset, power supplies and optics, and our noise and power guide explains why fanless gear suits a living space.
Buying guide
We'd buy pbtoast29's ER-4 titled tested at $72 delivered, a little under the band, and since it takes any standard C13 power cord, a missing cord costs you almost nothing. There are at least 53 for sale and most ask $75–130 delivered, so you can afford to wait for one titled tested or factory reset. It's fanless with the supply inside, needs no license, and has an RJ45 console as well as a reset button that brings it back at 192.168.1.1 with ubnt/ubnt. Check the label says ER-4, not the same-size ER-6P with five PoE ports, and look for a module in the SFP port if you need fiber, since none come in the box. Skip reprovisioned-tech's from a zero-feedback account and hek_lager's $252 ask.
$59.06est. delivered
The lowest delivered ER-4 here at $59. There's no cord in the photo and no test claim, but any standard C13 cord powers it, so ask the seller to confirm it boots.
Ubiquiti ER-4 EdgeRouter 4 Gigabit Ethernet High-Performance Network Router Unit
$72.00est. delivered
Titled tested and under the band. The photo shows no power cord, but it takes a standard C13 cord, so that's no real loss.
Ubiquiti Networks EdgeRouter 4 ER-4 Gigabit Router 4 Port USB - TESTED
$79.75est. delivered
Titled factory reset, which would put it at 192.168.1.1 with ubnt/ubnt, and the photo shows the power cord. Plug it in and log in, with no console cable needed.
Ubiquiti Networks EdgeRouter 4 ER-4 Black Wired Router 4-Port USB FACTORY RESET
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 15, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$59.06est. delivered
$43.11 + $15.95 shipping
Buy It Now$43.11
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
No cord in the photo and no test claim. The seller lists a second unit too.
Seller: bridge-8579
99.2% positive
Used$72.00est. delivered
$60.00 + $12.00 shipping
Buy It Now$60.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled tested. No power cord in the photo.
Seller: pbtoast29
100% positive
Used$79.75est. delivered
$65.00 + $14.75 shipping
Buy It Now$65.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled factory reset. Photo shows the power cord.
Seller: lvoong30
100% positive
Used$79.98est. delivered
$69.99 + $9.99 shipping
Buy It Now$69.99
Our take
Titled tested with cord, and the cord is in the photo.
Seller: sell-it-ks
99.8% positive
Used$90.00est. delivered
$75.00 + $15.00 shipping
Buy It Now$75.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Our take
eBay's catalog title, shared by other sellers, but a real photo. No test claim.
Seller: g3mac
100% positive
Used$129.99delivered
$129.99 · free shipping
Buy It Now$129.99
Our take
Titled complete in the box, and the photo is the retail box. Ask to see the router.
Seller: verit9s
100% positive
Used$83.07est. delivered
$75.00 + $8.07 shipping
Buy It Now$75.00
Check the seller
Zero-feedback account. No test claim.
Seller: reprovisioned-tech
No feedback yet
Used$252.04est. delivered
$228.26 + $23.78 shipping
Buy It Now$228.26
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Priced high
About three times the median ask, shipping from Canada.
Seller: hek_lager
100% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 15, 2026.
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