Firmware Updates Explained: The Software Layer Most People Never Think About
What firmware actually is and how it differs from regular software and OS updates, why firmware updates matter for security, and the real risks of installing them.
Part of our General Tech Concepts Every Buyer Should Understand guide.
Firmware updates run quietly in the background of countless devices, routers, smart home gadgets, headphones, cameras, and even the components inside a computer, yet most people rarely think about them the way they think about a phone’s operating system update. Understanding what firmware actually is, and why keeping it updated matters, fills in an important gap in everyday device maintenance that often gets overlooked.
What Firmware Actually Is
Firmware is a specific type of software permanently programmed into a piece of hardware’s dedicated memory chip, providing the low-level instructions that control how that specific hardware component operates. Unlike regular application software or a full operating system, which can be easily installed, removed, or replaced, firmware is more tightly and permanently tied to the specific hardware it runs on, providing the fundamental instructions a device needs to function at all, often before a more complex operating system even loads, if the device has one at all.
How Firmware Differs From an Operating System or App Update
A smartphone’s operating system update, like a new version of Android or iOS, changes the broader software experience: the interface, features, and how apps behave. A firmware update, by contrast, typically updates lower-level instructions controlling specific hardware components, like a phone’s cellular modem, camera sensor calibration, or Bluetooth radio, functioning beneath the operating system layer. Many devices without a full operating system at all, like a Wi-Fi router, a pair of wireless earbuds, or a smart light bulb, rely entirely on firmware to define their complete functionality, since they have no separate “app layer” running on top of it.
Why Firmware Updates Matter for Security
Firmware vulnerabilities can be particularly serious because firmware typically operates with deep, low-level access to a device’s hardware, sometimes with more privileged access than the operating system or regular applications running on top of it. Security researchers have documented real-world cases of firmware-level vulnerabilities in routers, IoT devices and computer components being exploited to gain persistent, hard-to-detect control over a device, since firmware-level compromises can sometimes survive even a full factory reset or operating system reinstall, precisely because they live below that layer. This is a significant reason security experts consistently recommend keeping firmware updated across all connected devices, not just the primary phone or computer operating system.
Why Firmware Updates Get Neglected So Often
Unlike phone and computer operating systems, which generally prompt users clearly and repeatedly about available updates, many devices, particularly routers, smart home gadgets and accessories, don’t proactively notify users about available firmware updates, or require navigating into a separate manufacturer app or web interface to check and install them manually. This friction is a major reason firmware on routers and IoT devices often goes unupdated for years, leaving known, publicly disclosed security vulnerabilities unpatched on devices that are frequently exposed directly to the internet.
The Real Risk of a Failed Firmware Update
Firmware updates carry a small but genuine risk that regular app updates don’t: if a firmware update fails partway through, due to a power interruption or connectivity loss during installation, it can potentially leave a device in a non-functional state that’s difficult or sometimes impossible to recover without specialized tools or professional repair, since the device’s fundamental operating instructions were left incomplete. This is why manufacturers generally recommend ensuring a stable power source and connection before starting a firmware update, and why some devices include a fallback recovery mechanism specifically to guard against this risk.
Bottom Line
Firmware provides the fundamental, low-level instructions that make hardware components function, sitting beneath the operating system layer most people are more familiar with, and keeping it updated matters significantly for security, particularly on internet-connected devices like routers that don’t always make update notifications obvious. Proactively checking for firmware updates on routers, smart home devices and accessories, rather than assuming they’ll prompt automatically the way a phone does, is a worthwhile habit for maintaining both device security and functionality.
Sources
- Cybersecurity research on firmware-level vulnerabilities and persistent exploits
- Manufacturer firmware update documentation for routers and IoT devices
- CISA (Cybersecurity and Infrastructure Security Agency), device firmware security guidance
- Academic research on firmware security and update mechanisms
