This page gives information on selecting fonts useful as coding fonts, e.g. source code in programming lan­gu­ages or web design languages.

A good coding font is absolutely critical for good coding productivity. There are several desiderata for choos­ing a cod­ing font:

• Font Type: usually the coding font must be a monospace font.
• Character Set: the font should have all characters needed by the language. For most languages, e.g. C or CSS, this is easy: these languages use only ASCII char­ac­ters, which are supported by nearly all fonts. But some languages, such as HTML, can use many more char­acters, e.g. unicode characters, or win­dows-1252 ac­cented characters, which many fonts don’t support.
• Distinct Glyphs: the font should have clearly distinct glyphs, e.g.: clearly dissimilar glyphs for si­mi­lar characters like O and 0, or like l,1, and I.
• Extra Large Punctuation: the font should have punctuation marks that are extra-large, e.g. so that . is clearly distinct from , and : is clearly distinct from ;.
• Legibility: the font should have clearly legible glyphs, e.g. characters should not be pale or tiny. Character size is a special concern: characters should be 1 small enough that as much code as pos­sible is visible at one time, but 2 large enough that the code is easy to read. This is a special concern for people who suffer from vision problems like hyper­opia.
• Ligatures: the font should have ligatures for operators — e.g. == for =​=, or != for !​= — iff the coder wants them and their text edi­tor supports them. NB​: you will have seen differences in == and != in the preceding sentence iff your PC has a font named in this page’s font stack. NB​: fonts which sup­port ligatures may not support every liga­ture you want; you must check.

I now use Input Mono as my coding font: it has a rich character set, distinct glyphs, extra-large punc­tu­a­tion, and is quite legible — though it has no ligatures, a feature I want only for pseudo-code. Be­fore us­ing the Input Mono font I used DejaVu Sans Mono, then Cascadia Code, then IBM Plex Mono, each a bit better for my purposes than the one before.