Thai font · OFL

Prompt

พร้อม

By Narongsak Chaiwong

Typography & Licensing Specialist, ThaiGraph · April 16, 2026 · Updated August 22, 2026

Information verified as of August 2026

อ่านหน้า ฟอนต์ Prompt เป็นภาษาไทย — พร้อมลิงก์ดาวน์โหลดและวิธีติดตั้ง →

<link href="https://fonts.googleapis.com/css2?family=Prompt:wght@400;700&display=swap" rel="stylesheet">

@import url('https://fonts.googleapis.com/css2?family=Prompt:wght@400;700&display=swap');

font-family: 'Prompt', sans-serif;

Reading in Thai? The Thai edition of this page — ฟอนต์ Prompt, with the same download links, install steps and licence detail written in Thai — is at /th/fonts/prompt/. Start there if Thai is the language you work in.

This English page is written for the other job: setting Prompt in an English-language or bilingual build. Webfont CSS, self-hosting, the weight system, and how the Latin side behaves next to the Thai.

What Prompt is

Prompt is a loopless Thai typeface paired with a geometric Latin sans-serif, designed by Cadson Demak and released free on Google Fonts under the SIL Open Font License in nine weights with matching italics — 18 styles in total. It covers Thai, Latin, Latin Extended and Vietnamese.

The name comes from the Thai word พร้อม, which means “ready” — the same sense as the English word, as the foundry notes in the description shipped with the font on Google Fonts. ThaiFaces records the publication year as B.E. 2558 (2015 CE); Google Fonts added the family to its catalogue on 20 June 2016, per the METADATA.pb entry.

The design objective is stated plainly in the project brief: a formal loopless Thai and sans Latin typeface drawing on Avenir and the early modernist era. The result works as body text and holds up as a display face at larger sizes.

Where to download Prompt free

Prompt is a free download straight from Google Fonts — no registration, no payment, and no paid tier to upgrade to. Three legitimate routes:

1. Google Fonts ZIP — open the Prompt specimen, click “Get font”, and download the ZIP containing all 18 .ttf files. Unzip and install per your operating system.
2. CSS embed — add https://fonts.googleapis.com/css2?family=Prompt:wght@400;500;700&display=swap in a <link> tag, then declare font-family: 'Prompt', sans-serif;. Nothing to host yourself. Note the semicolon-separated weight list: the two-dot range form does not work on this family, and the next section explains why.
3. GitHub source — the cadsondemak/prompt repository holds the original .ttf and .otf files under OFL-1.1, for self-hosting or modification.

To see how your own copy sets before you commit, run it through our Thai font tester.

One caution: third-party font aggregators sometimes redistribute older or altered builds of Prompt that are missing weights or mishandle Thai tone-mark positioning. Stick to Google Fonts or the Cadson Demak repository.

Loading Prompt as a webfont in CSS

Prompt has no variable build, so the Google Fonts range syntax fails on it: a request for family=Prompt:ital,wght@0,100..900;1,100..900 returns HTTP 400, and every weight you want has to be listed individually. A range URL copied from a variable-font tutorial does not degrade gracefully here: the stylesheet request fails outright and no Prompt loads.

The reason sits in the font’s own metadata. The METADATA.pb entry lists 18 separate static files and carries no axes block, and Google’s CSS API v2 reference defines the two-dot form as a request for “a range of a variable font axis”. No axis, no range.

A working three-weight loadout:

<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Prompt:wght@400;500;700&display=swap">

body { font-family: 'Prompt', sans-serif; }

To pull the whole family, list all 18 tuples: family=Prompt:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900. That URL returns 200 and 72 @font-face blocks, not 18 — each style is emitted once per unicode-range subset, across the four subsets described below. The reference asks for axes in alphabetical order and tuples sorted numerically; when we sent tuples out of order on 22 August 2026 the endpoint still answered 200, so treat the ordering rule as documentation hygiene rather than something that will break your build.

What it costs to load. Google serves Prompt v12 as WOFF2 split across four unicode-range subsets labelled thai, vietnamese, latin-ext and latin, so a page that sets only Thai and basic Latin never fetches the other two. Measured from the Content-Length headers on fonts.gstatic.com on 22 August 2026, the thai and latin subsets for Regular, Medium and Bold total 93,520 bytes — roughly 91 KB for a full three-weight bilingual loadout.

To self-host instead, take the files from the cadsondemak/prompt repository, which ships TTF and OTF builds under OFL-1.1, convert them to WOFF2, and write one @font-face rule per weight. The unicode-range splitting pattern for a Thai and Latin pair is set out in our Thai-Latin bilingual guide.

Is Prompt free for commercial use?

Yes. Prompt is released under the SIL Open Font License, which permits use, copying, embedding, modification and redistribution at no cost, including in commercial work. There is no paid licence tier — the full 18-style family is free.

What the OFL allows:

• Client work, logos, packaging, signage and commercial advertising
• Webfont embedding, and bundling inside apps and e-books
• Modifying the font files and redistributing derivatives under the same OFL

What it does not allow: selling the font files on their own as a product, and using the original Reserved Font Name on your modified version. Our Thai font licensing guide covers the practical detail.

The nine weights, and where Prompt Bold sits

Prompt ships nine weights from Thin (100) to Black (900), each with a matching italic, for 18 files in total — Prompt Bold is weight 700, not the heaviest cut in the family. The full list is confirmed by the METADATA.pb file in the google/fonts repository:

If you reached for Bold because you wanted more punch in a headline, skip to ExtraBold (800) or Black (900) — both are in the same download, nothing extra to fetch. In CSS, use font-weight: 700 for Bold and font-weight: 900 for Black.

Prompt has no variable build, no condensed cut and no looped variant. For web deployment, a three-weight loadout of Regular, Medium and Bold covers most UI needs and measures about 91 KB across the Thai and Latin subsets, as set out above. If it is the missing condensed cut you came for, ThaiGraph Condensed is a free condensed loopless option in four weights under the OFL.

Prompt versus Kanit

Both are loopless Thai sans families from Cadson Demak with nine weights each, but Kanit is strictly geometric and leans industrial, while Prompt rounds the corners and opens up the counters. The choice is about brand temperature, not technical capability.

• Choose Prompt when the brand wants modernity that stays approachable — cafés, boutique hotels, wellness, independent e-commerce
• Choose Kanit for a harder, more assertive voice — sports, automotive, technology, heavy promotional work
• Choose Mitr for humanist warmth, accepting six weights and no italics
• Choose K2D or Bai Jamjuree for a loopless voice that has not yet been used everywhere

Browse the whole field in our loopless Thai fonts category.

Character design and tone

Prompt uses a high x-height, soft circular curves, and short stems relative to its cap height, producing a rounder silhouette than other Cadson Demak loopless faces. The head of ก is a gentle open hook that leans slightly inward, giving a softer profile than Kanit’s more rigid opening.

Apertures on ถ, ภ and ร are open and wide, which keeps the face readable at small sizes despite the loopless construction. Stroke weight is essentially monolinear with subtle optical correction at joins. The official description notes that particular attention went into the size and position of Thai vowel signs and tone marks, and it shows: ไม้เอก above a Thin weight still reads at 10pt.

That same description carries a warning worth repeating: loopless construction makes certain Thai consonant pairs look alike, which can cause confusion in short strings such as labels and buttons. This is a property of loopless Thai in general, not a defect specific to Prompt — the background is in our piece on the loopless revolution.

The Latin companion is a geometric sans with rounded terminals on s, c and e. Numerals are lining and full-height. Compared with Kanit’s Latin, Prompt’s sits closer to Avenir, which the brief names outright as the reference.

Best use cases

Prompt works hardest on consumer brands that want warmth and modernity in one typeface, and it is one of the few free Thai families with a genuine italic at every weight. Strong fits:

• Boutique hotel and hospitality branding — signage, collateral, web
• Wellness, spa and beauty brands where geometric-with-softness reads as premium
• Independent F&B packaging, particularly specialty coffee and craft beverage
• Thai-English editorial work that needs real italics rather than a software slant
• Mobile-first Thai e-commerce where friendly UI type outperforms corporate sans

Where it does not fit: Thai government documents, where regulation still expects a looped face such as Sarabun, and technical Thai typography meant to sit beside IBM Plex, where Anuphan is the better match.

Pairing Prompt with Latin type in a bilingual layout

Prompt pairs best with Latin sans-serifs that share its soft geometric bones, and with a looped Thai face when you want contrast between headline and body. Three strong pairings:

• Poppins — a near-sibling geometric Latin, ideal for Thai-English headline and subhead pairing
• Sarabun — looped Thai for long-form body text while Prompt handles headlines
• Noto Sans Thai — a neutral fallback with wider character coverage for multilingual copy

Full bilingual pairing logic is in our Thai-Latin pairing guide.

Name variants, and what to put in font-family

The CSS family string is exactly 'Prompt' — one word, no “Thai” in it, no foundry prefix — and the static file names follow the pattern Prompt-Regular, Prompt-Bold, Prompt-BlackItalic. The names that trip people up when self-hosting:

• font-family: 'Prompt' — the only string the Google Fonts CSS returns. “Prompt Thai”, “Prompt Sans” and “Cadson Prompt” are not real family names and will silently fall through to your fallback.
• Prompt-Italic, not Prompt-RegularItalic — the 400 italic breaks the pattern that the other eight italics follow, per the METADATA.pb file listing.
• Prompt-ExtraLight / Prompt-ExtraBold — one word, no space and no hyphen inside “Extra” in the shipped file names.
• พร้อม — the Thai word the family is named after, meaning “ready”. If this is the spelling you searched for, the Thai edition of this page is the one you want.

Worth saying plainly for anyone arriving from an English search: this is a typeface released in 2015, unrelated to the sense of “prompt” used about AI models. If you are auditing a stylesheet and find font-family: 'Prompt', it refers to this Cadson Demak family.

Licensing

Prompt is released under the SIL Open Font License and is free for commercial use, modification, and bundling provided the original copyright and OFL notice stay with the files. Verify at the Google Fonts page or the Cadson Demak source repository, which states OFL-1.1.

To compare before committing, browse our full Thai font library or narrow to loopless Thai fonts.

Information verified as of August 2026