Spline Sans Mono Font: the ZIP below holds 2 font files with a variable weight axis and 555 glyphs, plus the OFL licence.
Yes — Spline Sans Mono is free for commercial use, including inside a product you ship
Spline Sans Mono is released under the SIL Open Font License 1.1 (OFL). You can use it in client work, logos, products you sell, apps, and print, without paying or asking permission.
It was designed by Eben Sorkin and Mirko Velimirovic, initiated by the Spline team, specifically for UI interfaces, checkout flows, and code rather than as a general-purpose monospace. The brief shows up in the feature set: this is one of the most feature-dense free fonts we’ve measured on this site.
We verified the license directly from the font file, not from a third-party listing. The embedding permission flag (fsType) is set to 0 — Installable Embedding, the least restrictive value in the OpenType spec.
Quick facts
| Designer | Eben Sorkin, Mirko Velimirović |
| Added to Google Fonts | March 2022 |
| Foundry | Sorkin Type |
| Version | 1.004 |
| License | SIL Open Font License 1.1 |
| Commercial use | Yes, no attribution required |
Embedding (fsType) | 0 — Installable, unrestricted |
| Weights | 5 (300 Light → 700 Bold) |
| Variable font | Yes, one axis (Weight 300–700) |
| Glyphs | 555 |
| Characters covered | 411 |
| OpenType features | 34 |
| Vietnamese support | No |
| Formats | Variable TTF |
Download Spline Sans Mono
What’s in the download
The download is a single ZIP containing 2 font files plus the licence:
| File | What it is |
|---|---|
| SplineSansMono-Italic[wght].ttf | Variable italic — 1 axis: Weight |
| SplineSansMono[wght].ttf | Variable upright — 1 axis: Weight |
OFL.txt travels with the files — keep it in the folder if you pass the font on to anyone else. Total download 150 KB.
The download includes the OFL license file. Keep it in the package if you redistribute the font.
Need a broader monospace family or a matching UI sans? We don’t currently have a Premium Spotlight pick in the monospace lane — browse monospace families on Creative Market if you need more weights or a paired proportional sibling.
Affiliate link — commission at no cost to you.
What the OFL license actually lets you do
You can:
- Use Spline Sans Mono in commercial projects, including client work you bill for
- Use it in a logo or brand identity and trademark that logo
- Sell products that use it — merchandise, packaging, book covers
- Embed it in websites, apps, games, PDFs and ebooks
- Modify it and redistribute your modified version
You cannot:
- Sell the font file on its own, outside a larger bundled product
- Distribute it without the OFL license file
- Release a modified version under a Reserved Font Name
No attribution is required in your design. The OFL only asks that the license travel with the font files.
Inside the file: 555 glyphs and 411 characters
Spline Sans Mono ships 555 glyphs covering 411 Unicode codepoints — a smaller charset than the text-focused fonts on this site, typical of a monospace built for code and UI rather than multilingual prose.
12 languages in full — Vietnamese not among them
Tested against the full alphabets of 15 languages, Spline Sans Mono fully covers:
Spanish · French · German · Portuguese · Italian · Polish · Czech · Turkish · Romanian · Hungarian · Dutch · Nordic (Danish, Norwegian, Swedish)
Vietnamese is not supported. The font covers only 17 of the 256 codepoints in the Latin Extended Additional block. If Vietnamese is a requirement, Newsreader on this site is fully covered instead.
Which Unicode blocks those 411 characters cover
| Block | Covered |
|---|---|
| Basic Latin | 95 / 96 |
| Latin-1 Supplement | 96 / 96 |
| Latin Extended-A | 115 / 128 |
| Latin Extended-B | 18 / 208 |
| Latin Extended Additional | 17 / 256 |
| General Punctuation | 16 / 112 |
OpenType features: 34, unusually dense for a free font
Spline Sans Mono carries 19 numbered stylistic sets (ss01 through ss19, minus ss13) on top of the standard set:
| Feature | What it does |
|---|---|
ss01–ss19 | 19 stylistic alternate sets — character-by-character shape variants |
salt | Stylistic alternates (general) |
dlig | Discretionary ligatures |
frac / numr / dnom | Fractions, numerators, denominators |
subs / sups | Subscript and superscript |
sinf | Scientific inferiors |
zero | Slashed zero |
case | Case-sensitive punctuation forms |
19 stylistic sets is far beyond what most fonts — free or paid — ship. In a monospace built for code, stylistic sets are typically used to toggle individual ambiguous characters (like 0/O, 1/l/I) independently, which matters more here than in a text face where one global “alternate” toggle is usually enough.
The weight axis: one continuous range
Spline Sans Mono is a variable font with a single Weight axis from 300 to 700, giving five named stops:
300 Light · 400 Regular · 500 Medium · 600 SemiBold · 700 Bold
The range stops at Bold rather than reaching Black/ExtraBold — reasonable for a monospace meant for sustained reading in an editor or terminal, where very heavy weights reduce legibility rather than add it.
A tall x-height (0.545) — drawn to hold at small sizes
| Metric | Value |
|---|---|
| Units per em | 2,000 |
| Ascender | 1,927 |
| Descender | −473 |
| Cap height ratio | 0.727 |
| x-height ratio | 0.545 |
The x-height ratio of 0.545 is the highest of any font covered on this site so far — monospace fonts built for code generally push x-height up, since every character occupies the same fixed width regardless and legibility at small sizes in an editor matters more than elegant proportion.
Right for code, wrong for running prose
Good fit: code editors, terminals, checkout/pricing UI, technical documentation, and any commercial project where license risk needs to be zero.
Poor fit: any project needing Vietnamese, and long-form prose — monospace fonts are inherently wider per character than proportional text faces, which slows reading over paragraphs.
More free monospace coverage
- Newsreader Font — for Vietnamese support or long-form text
- Schibsted Grotesk Font — matching proportional UI sans
License and technical data on this page was read directly from the font binary — fsType embedding bits, glyph counts, character coverage, and OpenType feature tables — not copied from a third-party listing. Last verified against Spline Sans Mono version 1.004.
Leave a Reply