GKrellM review
A free, open-source monitor for users who want broad system visibility in one window.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
GKrellM is a lightweight desktop system-monitoring application for users who want multiple system indicators displayed together in one window. It supports Windows, macOS, and Linux, making it suitable for cross-platform monitoring across personal computers and workstations. The product is aimed at people who need ongoing visibility into hardware, operating-system activity, connectivity, storage, power, and related system conditions rather than a broad collection of general-purpose desktop widgets.
Its main strength is the range of monitoring available in a single application. GKrellM can display CPU activity, including SMP CPU views, process load and counts, disk and filesystem capacity, network interfaces and TCP ports, memory and swap usage, temperatures, fan and voltage readings, disk temperatures, uptime, and battery status. It also includes mailbox monitoring for mbox, maildir, MH, POP3, and IMAP, along with clock, calendar, hostname, and other system displays. Configurable charts, alarms, themes, monitor-label commands, and plugins add control over how the information is presented and extended.
GKrellM is a strong fit for technically oriented users who value detailed monitoring, customization, and an open-source model. Remote data collection through gkrellmd can extend its monitoring beyond the local machine. At the same time, its identity is narrow: the product centers on system and hardware data, with a stacked-monitor presentation rather than a general desktop-widget toolkit. Users seeking broad lifestyle, productivity, or decorative widgets should choose a different category of software. For those focused on CPU, processes, storage, networking, memory, temperature, mail, and power indicators across Windows, macOS, and Linux, GKrellM offers a notably broad monitoring scope without a paid plan.
GKrellM pros and cons
- Where it wins
- Monitors CPU, processes, disks, memory, network, temperatures, and battery
- Supports Windows, macOS, and Linux
- Themes, alarms, charts, plugins, and remote data collection
- Where it doesn't
- Its primary focus is system monitoring rather than general-purpose widgets
- The stacked monitor layout may feel specialized for desktop customization
- Platform support relies on platform-specific builds and packages
GKrellM fact sheet, pricing and score →
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