If you tried to use a third-party monospaced font (e.g., Courier, Menlo, or Fira Code) via a configuration profile, iOS would frequently misinterpret non-breaking spaces ( ), tab characters, and consecutive whitespace. The result? Alignment columns in code editors would shatter, ASCII art would look like abstract modern art, and coding notes would become unreadable.
The iOS 15.4 update refined how the engine handles font descriptors. By ensuring that the "fixed-pitch" attribute is strictly honored, Apple eliminated the erratic character jumping that occurred during rendering. This fix was particularly vital for the SF Mono typeface and other professional fonts like Fira Code or JetBrains Mono that users frequently download to customize their iPad or iPhone development workflows. Impact on the Developer Ecosystem ios 15.4 fixed space -font- download
Safari 15.4 (bundled with iOS 15.4) added support for the ic unit, which is equivalent to the width of a specific glyph in the current font, aiding in more precise web layouts. If you tried to use a third-party monospaced font (e