Mectrics
A free, open-source Mac menu bar app that shows CPU, memory, battery, network, disk, GPU, temperature and fan metrics at a glance.
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Description
If your Mac ever slows down or the fans suddenly kick in, the built-in Activity Monitor makes you dig through a whole window just to see what's going on. Mectrics puts the same information one glance away, permanently docked in your menu bar, so you can spot a runaway process or an overheating machine before it becomes a real problem — without opening anything.
Mectrics is a native macOS menu bar app that displays real-time system metrics — CPU (including per-core detail), memory, battery, network throughput, disk usage, GPU, temperature and fan speed — with small sparkline trend graphs and detailed popovers for each metric. It ships a "Compact Health" mode that collapses everything into a single icon that only changes when something is actually wrong, plus a command-line interface for scripting and headless Mac automation with alert event streaming. The app reads all metrics locally (zero telemetry, no analytics, no crash reporting), is signed and notarized, MIT-licensed, weighs about 27 MB of RAM, and requires macOS 15 (Sequoia) or newer.
💬 Our review
The short version: Mectrics is a free, open-source, privacy-respecting system monitor for the Mac menu bar — lighter and simpler than the paid alternatives, with a CLI that most competitors don't offer.
The closest comparison is Stats (exelban/stats), the other well-known free, open-source menu bar monitor — it has a much bigger GitHub following and a longer track record, so it's the safer bet if you want a mature, actively-community-tested tool. Mectrics is newer (135 GitHub stars at the time of writing) but differentiates with a genuinely useful CLI for headless Mac automation and an explicit zero-telemetry stance. Against iStat Menus, the long-standing paid option, Mectrics obviously loses on polish and feature depth (no historical logging dashboards, no widgets beyond basic WidgetKit support) but wins on price — free is free. If you just want a clean, no-nonsense system readout without paying or worrying about a subscription, Mectrics is a solid pick; if you need the deepest historical reporting and don't mind paying, iStat Menus remains the more mature choice.
💰 Pricing
📊 Global score
🤖 AI-enriched data
Application 100% gratuite et open source (licence MIT), téléchargement direct signé et notarié pour macOS 15 (Sequoia) et plus récent. Aucune offre payante.
Pros
Zéro télémétrie, aucune donnée envoyée — tout est lu localement
Empreinte très légère (~27 Mo de RAM, quelques % de CPU)
CLI dédiée pour automatisation et Mac headless (streaming d'événements d'alerte)
Multilingue (6 langues) et open source sous licence MIT
Cons
macOS 15 (Sequoia) minimum requis, aucune rétrocompatibilité
Pas de version Windows ou Linux
Projet jeune (135 stars GitHub) face à Stats, bien plus établi
Pas de tableaux d'historique avancés comme sur iStat Menus (payant)