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Setting Up a Custom UI Font in Arc

Setting Up a Custom UI Font in Arc

Arc lets you change the font used across its user interface so it can match your organisation's branding or your own readability preferences. The custom font is defined in the settings.yml configuration file on the Arc server, so it is applied once by an administrator and takes effect for every user of that Arc instance.

Two font sources are supported:

  • A Google Font, referenced by name and loaded from fonts.googleapis.com.

  • A self-hosted font file placed on the Arc server by an administrator, for environments that cannot make outbound calls to Google.

This is an administrator task. Setting the UI font requires access to the Arc installation directory on the server and the ability to restart Arc. End users cannot change the UI font themselves. For security reasons, Arc does not allow fonts to be uploaded through the interface.

Before you begin

Make sure you have:

  • Access to the Arc installation directory on the server, where settings.yml is located.

  • Permission to edit settings.yml and to restart Arc.

  • The font you want to use, either the exact Google Font name or the font file you intend to host on the server.

Step 1: Choose your font source

Decide where the font will come from before editing any configuration.

Option

Best for

Requirement

Option

Best for

Requirement

Google Font

Quick setup using any font from the Google Fonts library.

The browser must be able to reach fonts.googleapis.com (outbound internet access).

Self-hosted font file

Locked-down or offline environments with no outbound internet access.

An administrator hosts the font file on the Arc server (or another location the browser can reach).

Step 2: Set the font in settings.yml

Open the settings.yml file in the Arc installation directory and add (or update) the font setting.

Option A: Use a Google Font

Set the font to the exact name of the Google Font you want, for example Inter:

# The font family used across the Arc user interface font: Inter

The font name must match the Google Fonts name exactly, including capitalisation and spaces. Arc loads the matching font from fonts.googleapis.com.

Option B: Use a self-hosted font

If you cannot reach Google Fonts, an administrator hosts the font file (for example a .woff2, .woff or .ttf file) on the Arc server, then references it from the font setting so the browser loads it from your own environment instead of from Google.

Only an administrator with server access can add a self-hosted font. The file has to be placed on the server manually, which keeps untrusted fonts out of the interface.

Step 3: Restart Arc and refresh

  1. Save settings.yml.

  2. Restart Arc so it picks up the new configuration.

  3. Ask users to refresh their browser (a hard refresh clears any cached fonts).

Arc now displays its interface in the custom font.

Quick reference

Item

Value

Item

Value

Configuration file

settings.yml (in the Arc installation directory)

Setting

font

Google Font source

fonts.googleapis.com (outbound access required)

Restart required?

Yes, restart Arc after saving

Who can change it?

Administrators only (server-side)

Security and network notes

  • Administrator only. Fonts can only be added by someone with access to the Arc server. Uploading fonts through the Arc interface is intentionally not supported.

  • Outbound dependency for Google Fonts. The Google Font option makes an outbound request to fonts.googleapis.com. In locked-down environments, either allow that domain or use a self-hosted font instead.

  • Font names are sanitised. Arc cleans the font value before it is applied, so invalid or unsafe font names are rejected.

Troubleshooting

Symptom

What to check

Symptom

What to check

The font does not change after saving

Confirm Arc was restarted, then do a hard refresh in the browser to clear cached fonts.

A Google Font is not loading

Check the spelling and capitalisation of the font name against the Google Fonts library, and confirm the browser can reach fonts.googleapis.com.

Offline or locked-down server

Use a self-hosted font file instead of a Google Font.

Related pages