Thai font · COMMERCIAL

Silom

สีลม

By Narongsak Chaiwong

Typography & Licensing Specialist, ThaiGraph · July 4, 2026

Information verified as of July 2026

What Silom is

Silom is Apple’s loopless Thai display system font, first bundled with Mac OS X 10.3 Panther in 2003 and still shipping with macOS today — Apple’s official font list for macOS Monterey records it as “Silom 14.0d1e1”. It is preinstalled on every Mac, so Thai designers on Apple hardware have had it available for free-at-point-of-use display work for over two decades.

The name (สีลม) comes from Si Lom Road, the spine of Bangkok’s main business district. That fits the naming pattern of Apple’s Thai system font family, which reads like a Bangkok street map: Krungthep, Thonburi, Sathu, Ayutthaya, and later Sukhumvit Set.

One disambiguation matters. A free-for-personal-use “Silom” by Tom Tor circulates on font download sites — that is an unrelated 8px Latin-only bitmap font that merely shares the name. Its license and designer credit do not apply to Apple’s Thai Silom.

Character design and tone

Silom pairs a loopless Thai character set with Latin letters taken directly from Chicago, the 1984 Macintosh UI typeface from the Susan Kare era — Wikipedia notes that Krungthep and Silom “use Chicago for their Latin letters and hence can be used as modern replacements” for that historic face. The result is a chunky, retro-interface display voice that no other Thai system font has.

The Thai set is loopless: consonants drop the traditional หัว (loop terminals), giving the face a simplified, modern silhouette even though its lineage reaches back to Apple’s early-1990s Thai localization work (the embedded copyright reads 1992–2011). Strokes are heavy and evenly weighted, matching Chicago’s bold bitmap-era proportions, so mixed Thai-Latin settings like “สวัสดี Macintosh” sit on one visual rhythm.

Per the ThaiFaces specimen, coverage includes the full Thai consonant, vowel, tone-mark, and Thai-numeral set, so running Thai text renders completely — it is the tone of the face, not missing glyphs, that limits it to display sizes.

Weights and availability

Silom ships in a single Regular weight, preinstalled with macOS — there is no legal standalone download, and Apple does not sell it separately. A 2004 review of Thai support on the Mac confirms this was true from the start: Panther’s five additional Thai fonts (Ayutthaya, Bangkok/Krungthep, Sathu, Silom, Thonburi) were all supplied in regular weight only.

One weight means no typographic hierarchy within the family. If a project needs Light-to-Black range in a loopless Thai voice, use an open-licensed family such as Kanit or Prompt instead — see our typography guide for building Thai type hierarchies.

Best use cases

Silom fits retro-Mac and nostalgia-driven Thai display work on Apple platforms, where its Chicago Latin reads as a deliberate design reference. Sensible briefs:

• Retro interface homages and pixel-era visual identities for Thai audiences
• Display headlines in Mac-native design, video, and motion work
• Bilingual Thai-Latin lockups that trade on classic Macintosh character
• Personal and internal projects produced entirely on licensed macOS machines

Where it doesn’t fit: web embedding and cross-platform products (the font cannot legally be redistributed with a site or app), any project needing multiple weights, and long-form body text — for those, reach for Kanit, Prompt, or another open-licensed display family.

Pairings

Silom carries the display layer; pair it with a quieter Thai text family for everything below the headline. Three pairings:

• Sukhumvit Set — Apple’s modern Thai UI family, the natural body companion inside the same macOS ecosystem
• Sarabun — open-licensed Thai body sans when the project must also ship on the web
• Kanit — geometric loopless sans for mid-level hierarchy that echoes Silom’s simplified forms

Licensing

Silom is proprietary Apple software, bundled with macOS under Apple’s software license agreement — it is not separately sold, and there is no legal free download. The embedded notice reads “Copyright (c) 1992-2011 by Apple Inc. All rights reserved.” Use it within the terms of your macOS license; do not embed it in websites, apps, or products, and do not download “Silom” files from free-font sites, which carry the unrelated Tom Tor bitmap font. For a loopless Thai display voice under an open license that you can deploy anywhere, use Kanit or Prompt, both free for commercial use.

Information verified as of July 2026