System Monitor Card

Features

• Two cards: a full System Monitor Card and a compact System Monitor Mini Card
• Zoom on the mini card: a button at the top right switches it to the full System Monitor card (same options) and back; a click anywhere outside the card brings it back too
• Automatic discovery of the System Monitor entities through the entity registry (any language)
• CPU, RAM, disk and CPU temperature gauges, uptime, load average and IP address
• Home Assistant Core and OS versions, with an orange badge when an update is available
• Network download / upload rates and totals, per interface (virtual interfaces such as docker0 or hassio are hidden)
• 24 h history: a discreet curve of the last 24 hours behind the CPU and RAM gauges (bars on the mini card) and each download / upload rate, on the full card and the mini card, from the recorder's statistics on a real time axis, with a break where the recorder has no data (refreshed every 5 minutes; show_history: false turns it off)
• Storage: every monitored mount point and the swap, with used space, and the size of the Home Assistant database
• Backups: when the last automatic backup was made and when the next one is due, orange / red when it gets old or the last attempt failed (the mini card shows it only then), from Home Assistant's own backup sensors
• Monitored processes, green when running and red when stopped: hidden while they all run (their status tile shows the list on a click), always shown while one is stopped, with their overall status in the status row
• Colors turn orange / red when a threshold is crossed (CPU, RAM, disk, temperature, swap), with thresholds you can change
• Click any value to open its Home Assistant history (more-info dialog)
• Visual editor in the dashboard UI for every card (no YAML needed)
• Light and dark mode, English, French, German, Spanish, Serbian (Cyrillic and Latin), Italian, Dutch, European Portuguese, Polish, Romanian, Danish, Swedish, Bulgarian, Russian, Ukrainian, Hungarian, Slovak, Czech, Slovenian, Latvian and Greek
• Single file, no external dependency

Supported integrations

The Marketplace updates and the unavailable integrations have their own cards: Marketplace Refresh and Integration Watchdog.

Prerequisites

Home Assistant 2024.8 or later, and:

The System Monitor integration must be added (Settings → Devices & services → Add integration → System Monitor).

Most of its sensors are disabled by default: open the System Monitor device and enable the ones you want to see on the card, for example:

Sections and gauges without any enabled sensor are simply not displayed.

Configuration

Visual editor#

Edit a dashboard, click Add card and search for System Monitor Card or System Monitor Mini Card. Set an optional title, choose the sections to display, the network interface and the language. The preview updates live, and options left at their default are kept out of the generated YAML.

Minimal#

type: custom:system-monitor-card

type: custom:system-monitor-mini-card

Full options#

type: custom:system-monitor-card
title: My Home Assistant
show_system: true
show_network: true
show_history: true
show_storage: true
show_backups: true
show_processes: true
interface: eth0
language: fr
cpu_warning: 70
cpu_critical: 90
ram_warning: 80
ram_critical: 95
disk_warning: 80
disk_critical: 90
temp_warning: 75
temp_critical: 90
swap_warning: 50
swap_critical: 80
backup_warning: 2
backup_critical: 7

type: custom:system-monitor-mini-card
title: My Home Assistant
show_storage: true
show_network: true
show_history: true
zoom: true
interface: eth0
language: fr
cpu_warning: 70
cpu_critical: 90

Options reference#

How it works

The cards read the entity registry of Home Assistant and keep the entities of the systemmonitor platform. Each sensor is recognized by its translation key (processor_use, memory_use_percent, disk_free, throughput_network_in…), so entity ids translated in another language (for example sensor.system_monitor_utilisation_du_processeur) and renamed entities are supported. Mount points, interfaces and process names are read from the end of the sensor name, after the device name and the label: a mount point starts at its first / (so names with spaces, /mnt/My Passport, are kept whole), an interface is the last word, a process name is what follows Process (or the label the other processes share). This works for a sensor alone of its kind too (Disk usage /config). A sensor renamed in its entity settings (WAN up, Root free) no longer says its argument: it is read from its entity id instead, which Home Assistant made from the original name (sensor.system_monitor_network_throughput_out_eth0 → eth0, sensor.system_monitor_disk_free → /). When the registry is not available, English entity ids (sensor.system_monitor_processor_use…) are used as a fallback.

The Core and OS versions come from the update.home_assistant_core_* and update.home_assistant_operating_system_* entities when they exist, otherwise from the running Home Assistant version.

Status row#

Under the header, a tile gives the overall status of the Processes section (running or the number stopped), green when all is well, red otherwise. The Core / OS update badge turns grey "Unknown" when the update entity is unavailable. Click the tile to show the section unfolded; a click elsewhere folds or hides it again. The Home Assistant Core / OS update stays next to the logo. The tile is left out when the section is hidden or has no process.

Mini card#

The compact card shows CPU, RAM, disk and temperature bars, then the Core / OS status, the network rates and the uptime. While a monitored process is stopped, its header icon turns red and its footer shows a red "N stopped" item: a click on it shows the full card with the processes list unfolded (with zoom: false, it opens the first stopped process). At the far right of the header, a small round button (mdi:arrow-expand) shows the full card in its place, with the same options, exactly as the System Monitor Card shows it, and turns into mdi:arrow-collapse to bring the compact view back; a click anywhere outside the card does too, but not a click in a dialog opened from it (more-info). zoom: false removes the button.

Processes#

The processes section is hidden while every monitored process runs: the Processes tile of the status row says "Running", and a click on it shows the list, which hides again on a click on its title or elsewhere. As soon as a process is stopped, the section shows up by itself and stays, whatever you click, until every process runs again. Its title shows the number of processes, and the number stopped in red.

Backups#

The Storage section also shows Home Assistant's automatic backups, from the sensors of the built-in Backup integration (Home Assistant 2025.2 or later, nothing to set up): Last successful automatic backup, Last attempted automatic backup, Next scheduled automatic backup and Backup manager state. The row shows when the last one was made and when the next one is due; it turns orange after backup_warning days, red after backup_critical days, when the last attempt failed or when there was never one, and says Backing up… while one runs. Click it for the sensor's history. Only automatic backups count (set them up in Settings → System → Backups).

Database size#

The Storage section ends with the size of the Home Assistant database (the default SQLite one, home-assistant_v2.db), read from the File Size integration. To get it:

1. Allow Home Assistant to read the file, in configuration.yaml, then restart:

   homeassistant:
     allowlist_external_dirs:
       - /config
   

2. Settings → Devices & services → Add integration → File Size, with the path /config/home-assistant_v2.db.

The card finds its size sensor by itself (platform filesize, a file named home-assistant_v2.db); a click on the row opens its history. Without it, the row is not shown. An external database (MariaDB, PostgreSQL) is not a file and isn't supported.

Thresholds#

Gauges and bars turn orange, then red, when a value reaches these thresholds (the defaults; each can be changed with the *_warning / *_critical options, in YAML or in the visual editor):

The CPU temperature is shown in the unit of its sensor, which follows the unit system of Home Assistant (°C, or °F with US customary units) or the display unit chosen in the sensor's settings; the thresholds are in °C and apply to the same temperature in any unit.

Support

If you find this project useful, you can support its development:

Maintenance

• No code change: released again to check the installation from the Marketplace.

Features

• Backups: the full card's Storage section shows when Home Assistant's last automatic backup was made and when the next one is due, from the built-in Backup integration's sensors (no setup). It turns orange after backup_warning days (2), red after backup_critical days (7), when the last attempt failed or when there was never one, and says Backing up… while one runs. The mini card shows an orange / red item only then. show_backups: false hides it.

Fixes

• Translations: the cards are defined once the page's language file has arrived (at most 1.5 s; Home Assistant builds a card when its element gets defined), so the first render is already translated instead of English then redrawn; until a language file is in, a missing text reads the English one wherever the card has no fallback of its own.

Performance

• Translations load on demand: the bundle keeps English only (124 KB → 87 KB) and each other language is its own system-monitor-card.i18n.<lang>.js file next to it, fetched the first time a card needs it. Home Assistant loads every dashboard resource on every dashboard, so each page used to download and parse all 22 languages to use one. Until a language file has arrived (a few milliseconds), texts fall back to English, and the cards redraw once it is there.

Maintenance

• Build: scripts/i18n-split.mjs splits the built bundle and rebuilds every table from the split files to check them (the build fails on any difference); src/ keeps every language as before.
• Release: every file of dist/ is attached. Manual installation copies the translation files too.

Fixes

• Gauges "used / total" detail: the used value keeps its unit when it differs from the total's ("980 MiB / 62.5 GiB" instead of "980 / 62.5 GiB").
• Storage bars: the percentage is rounded like the gauges' (same display helper as the other cards).

Features

• Mini card, stopped processes: while a monitored process is stopped, the compact view tints its header icon red and shows a red "N stopped" item in its footer, whose click shows the full card with the processes list unfolded (or, with zoom: false, opens the first stopped process).
• 24 h CPU and RAM history: a discreet curve of the last 24 hours behind the CPU and RAM gauges of the full card and the CPU and RAM bars of the mini card, on a 0–100 % scale, from the same statistics query as the rate curves; show_history (now labelled "Show 24 h history" in every language) turns them all off.

Maintenance

• Screenshots: the mock Home Assistant answers the statistics query with plausible CPU and RAM percentages.
• Tests: the stopped item and the red icon of the mini card (zoom, zoom: false, show_processes: false, full view), the CPU and RAM curves, the single query and its statistic ids.