“Supports Vietnamese” usually means someone guessed
Search any free-font roundup for “best fonts for Vietnamese” and you’ll get lists built from vendor marketing copy — “supports 40+ languages” banners that rarely specify which 40. Vietnamese is a demanding case: it needs precomposed characters for every combination of a base Latin letter, a diacritic mark (circumflex, breve, horn), and a tone mark (acute, grave, hook, tilde, dot below) — stacked two and sometimes three deep, like ệ, ữ, ỗ.
A font can claim broad “Latin Extended” support and still be missing exactly the combinations Vietnamese needs, because most of those combinations live in a specific Unicode block — Latin Extended Additional (U+1E00–U+1EFF) — that a lot of font families simply don’t fill out.
We don’t guess. We test the character set of every font against a probe string covering every precomposed Vietnamese character and report only what’s actually there.
How the test works
Each font’s cmap table is checked against 134 precomposed Vietnamese characters (uppercase and lowercase) spanning the six base vowels that take Vietnamese-specific diacritics (ă, â, đ, ê, ô, ơ, ư) combined with all five tone marks. A font either has the glyph for a given codepoint or it doesn’t — there’s no partial credit at the character level, though we do report fonts that cover most but not all of the set as partial.
“Full support” below means 100% — every character in the test set is present as an actual glyph in the font file.
Verified full support
| Font | Glyphs | Latin Ext. Additional coverage | Best for |
|---|---|---|---|
| Bitter | 1,542 | 164 / 256 | Long-form reading, editorial, documentation |
| Recursive | 1,304 | 164 / 256 | Product UI, code + interface systems |
| Space Grotesk | 1,001 | 168 / 256 | Tech/SaaS branding, dashboards |
| Fraunces | 698 | 154 / 256 | Editorial headlines, packaging, wedding |
| Bricolage Grotesque | 597 | 97 / 256 | Product marketing, SaaS landing pages |
All five pass the full stacked-diacritic test — ệ, ữ, ỗ, ẫ, ặ and every other combination render correctly, not as a base letter with a floating mark or a missing-glyph box.
Note the coverage numbers don’t need to hit 256/256 to fully support Vietnamese — the Latin Extended Additional block also contains characters for Vietnamese-adjacent needs and other Latin-based languages that Vietnamese text doesn’t use. What matters is whether the specific 134 Vietnamese-relevant characters are present, and for all five, they are.
Also worth noting: glyph count doesn’t predict this. Bricolage Grotesque has the fewest total glyphs of the five (597) and still passes completely — it’s a display font with a narrow overall character set that was still built out carefully where it counts. Don’t assume “more glyphs” means “better Vietnamese support.”
A real failure case: Caveat
Not every font on this site passes. Caveat, the popular free casual handwriting font, only reaches 34 of 256 characters in the Latin Extended Additional block — it covers Cyrillic fully but leaves most Vietnamese stacked-diacritic combinations unsupported. We’re flagging it rather than quietly leaving it off this list, because “which fonts fail” is exactly the information vendor pages never volunteer. See the full Caveat breakdown for what specifically is and isn’t covered.
Why this happens: a common failure pattern
Across the free-font space generally, the most common way a font fails this test isn’t missing Vietnamese entirely — it’s covering the base diacritics (ă, â, ê, ô, ơ, ư without tone marks) but not the stacked combination with a tone mark on top. That’s the harder engineering problem: it means drawing and hinting dozens of extra precomposed glyphs rather than relying on generic mark-positioning. A font that handles French or Spanish accents fine can still fail here, because Vietnamese stacking depth is unusual even among Latin-script languages — Caveat above is a direct example: strong Cyrillic coverage, weak Vietnamese coverage, in the same file.
If you’re evaluating a font that isn’t listed on this page yet, the fastest manual check: type “tuyệt vời” in it. If both words render with intact stacked marks and no visible substitution box, it’s a reasonable sign — though the full test above checks the entire character set, not just one phrase.
Related
- Fraunces Variable Font: 4 Axes Explained
- Space Grotesk: Full OpenType Feature Breakdown
- Bitter: Variable Slab Serif Explained
- Recursive: 5 Variable Axes Explained
- Bricolage Grotesque: 3-Axis Variable Font Explained
- Caveat: Why It’s Not Vietnamese-Safe
This list is a living page — updated as more fonts are tested. Every entry is verified directly against the font binary, not copied from a vendor’s language-support claim. Last updated: [date].
