When comparing Google Roboto Mono vs Iosevka, the Slant community recommends Iosevka for most people. In the question“What are the best programming fonts?” Iosevka is ranked 6th while Google Roboto Mono is ranked 26th. The most important reason people chose Iosevka is:
Iosevka is very clear and legible on all displays and in all sizes.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Looks really beautiful
Roboto Mono has a very clean and beautiful design.
Pro Clean and legible
Roboto Mono is crystal clear which makes it a good choice for reading code without your eyes getting tired.
Pro The right thickness
It's neither too thin, too fat, nor too condensed. Roboto Mono is just right.
Pro All variants available
Both bold and italics look great in Roboto Mono.
Pro Distinctive uppercase vs lowercase characters
The median line is placed relatively low. This makes reading mix-cased words (eg. hashes) easier.
Pro Readable, elegant and cute
It's very readable, elegant and cute. Almost indistinguishable with SF Mono at small point sizes. It looks great even as a display font.
Pro Makes for an excellent font for terminal
Roboto Mono looks particularly well on iterm2.
Pro Released under the lenient Apache License
Pro Powerline Patched version works well
This is the only font that works well and looks good with agnoster theme and powerline for bash/zsh.
Pro Looks great on HiDPI
Looks good at 14pt and lower, but looks great at 20pt and higher, making it an excellent font for higher resolutions
Pro Readable
Iosevka is very clear and legible on all displays and in all sizes.
Pro Narrow
Narrow character width uses horizontal screen space more efficiently.
Pro Large number of weights
This font comes in seven different weights, ranging from thin and extra-light to heavy.
Pro Great customizability
There is full customization of styles and variants in Iosevka.
Pro Support for Cyrillic and Greek letters
Iosevka is quite flexible in that it supports Cyrillic and Greek letters.
Pro Free and open source
Iosevka is free and open source.
Pro Powerline support
Includes characters for supporting Powerline/Airline for terminals and terminal editors.
Pro Ligature characters look great
Few fonts have a good ligation feature. Ligature characters (such as æ or the German ß) are supported in Iosevka and look just as you'd expect them to.
Pro Several styles available
Many of the common styles are available, including Sans Serif and Slab Serif with normal, bold, italic, and bold italic styles.
Pro IPA Support
IPA is a system containing the sounds of spoken language and includes speech qualities such as intonation.
Pro Easy on user's eyes
Due to it being readable on all types of displays, Iosevka isn't hard on the user's eyes.
Pro Well-maintained
The developer is active and responds to user questions and issues.
Pro Good CJK compatibility
Iosevka integrates CJK characters well, those being characters of the Chinese, Japanese, Korean, and occasionally Vietnamese languages.
Pro Also variant with tiny serifs available ("Slab")
For better reading longer texts.
Cons
Con Curly braces aren't very distinctive
The curly braces are too close to parentheses, which can harm readability for programming.
Con Not recognized as monospace font
Windows does not recognize the font as monospaced. Cannot be used as terminal font.
Con Sublime Text doesn't show italic version
font face "Roboto Mono" has different widths for italic characters, disabling to prevent text reflow
Con Too narrow
Con Must do a custom build to get all ligatures
Con Fewer ligatures than other fonts
Iosevka has a nice ligation set, but it doesn't have as many ligatures as fonts like Hasklig, Monoid, or Pragmata Pro.