# brektrou/rtl8821CU

Realtek RTL8811CU/RTL8821CU USB Wi-Fi adapter driver for Linux

Repository: https://github.com/brektrou/rtl8821CU
Canonical: https://ross.abutalabs.com/products/rtl8821cu
Language: C
License: GPL-2.0
License Family: copyleft
Last push: 2023-12-25T20:51:52+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 2742, "days_push": 982, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1723, forks 469 (observed 2026-08-28T04:05:27.937965+00:00)

## What it is
An out-of-tree Linux kernel driver for Realtek RTL8811CU/RTL8821CU USB Wi-Fi adapters, written in C. It supports DKMS-based automatic rebuilds across kernel updates and includes usb_modeswitch guidance for adapters that start in CD-ROM mode.

## Use cases
- get a Realtek RTL8821CU USB wifi dongle working on Linux
- install a kernel driver for an 802.11ac USB adapter that Linux doesn't recognize
- make a USB wifi adapter survive kernel updates with DKMS
- switch a Realtek USB wifi adapter out of storage mode with usb_modeswitch
- build the rtl8821CU driver from source on Ubuntu or Arch

## When to choose
- you have an RTL8811CU/RTL8821CU-based USB Wi-Fi adapter that isn't supported by the in-kernel driver
- you run Linux 4.4 through 5.x and need a working 802.11ac USB dongle
- you want DKMS to automatically rebuild the module on kernel upgrades

## When to avoid
- your adapter uses a different Realtek chipset (e.g. RTL8812AU or RTL8188EU)
- your kernel version is newer than what this driver supports and an in-kernel or vendor driver exists
- you need a maintained driver with active upstream development

## Facets
- artifact type: library
- maturity: maintenance
- function: networking, embedded
- domain: hardware, operating-systems
- platform: -
- tags: wifi-driver, kernel-module, realtek, usb-wifi, dkms, rtl8821cu, linux

## Member repositories
- brektrou/rtl8821CU (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:27.937965+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:33:57.195935+00:00, confidence not recorded.
  - readme: https://github.com/brektrou/rtl8821CU (fetched 2026-08-28T04:05:27.937965+00:00, sha cbee74f048b5)
- Data as of 2026-08-30T08:39:29.467469+00:00.