Does the Bold Text accessibility setting change your iPhone keyboard?
Bold Text makes iOS redraw system type with a heavier stroke — Messages, Mail, Settings, the keyboard’s own suggestion bar — without touching size or layout. A custom keyboard draws its own key labels from scratch, so the switch only reaches them if the keyboard’s code checks for it.
You turned on Bold Text because the ordinary weight of iOS type is too thin to read comfortably at a glance, and now you are wondering whether it reaches the keyboard too — specifically the one you installed, with its own key labels, rather than Apple’s. It is a fair thing to check, because the setting genuinely reaches some letters on your screen and not others, and which is which depends on who actually drew them.
What Bold Text actually does
The switch lives at Settings → Accessibility → Display & Text Size → Bold Text, on the same screen as Reduce Transparency, Reduce Motion and Larger Text, which is part of why people mix the four up. Turning it on swaps every letter iOS draws itself — Home Screen labels, Mail, Messages, Settings’ own menus, notification banners — from the system font’s regular weight to a heavier one. Of the four settings on that screen, it is the one that touches only weight: nothing gets bigger, nothing stops moving, nothing loses its blur. Just a heavier stroke on every letter the system draws.
How it differs from Larger Text
Larger Text, covered in a separate guide, scales the size of text through Dynamic Type — a scale each app has to opt into deliberately, which is why the effect varies so much from one app to the next. Bold Text is a completely separate trait, checked separately by whatever code is drawing the letter. The two toggle independently: on together, one without the other, or neither, in any combination, because they are answering different complaints even though Apple grouped them on the same screen.
A trait other software can read, not a filter stamped over everything
This works the same way as Reduce Transparency and Reduce Motion, covered elsewhere. Bold Text is not something iOS paints over the finished screen after every app has already drawn to it — it is a flag other code can check and choose to act on. iOS applies it automatically to the text it draws with its own system font: system menus, Mail, Messages, and the parts of a keyboard that are genuinely system-drawn, like Apple’s predictive-text suggestion bar. Those all live inside iOS’s own code, so Apple can guarantee the setting is honoured there because Apple wrote both sides of that agreement.
Once you are looking at a letter some other piece of software drew for itself, that guarantee ends. iOS has no mechanism to reach into someone else’s view and re-render a letter it did not draw. Whether Bold Text reaches it depends entirely on whether that code checked the flag and built a heavier version of its own font for when it is on.
Where that leaves a custom keyboard’s key labels
A third-party keyboard draws every key label itself, in whatever font and weight its own theme chose, the same way it draws the key’s background colour and corner radius — none of that passes through the system text layer Bold Text reaches. So a keyboard whose labels were already drawn at a fixed weight looks identical with the switch on or off, unless its developer specifically checked the flag and swapped in a heavier font for when it is turned on. Same architecture, same caveat, as Reduce Transparency and a keyboard’s own theme.
What does change on Apple’s own keyboard
This is why the question comes up at all: on Apple’s keyboard, the letters printed on each key, the suggestion bar text above them, and labels like “return”, “space” and “123” are drawn through the same system text-rendering Apple’s own apps use, so Bold Text reaches every one of them the moment you turn it on. That is the baseline people are comparing a third-party keyboard against, and the two can legitimately look different in this one respect without either one being broken.
Where Kibo fits
Kibo’s 56 themes each set their own key-label colour and weight as part of the theme itself, drawn independently of the system text layer Bold Text reaches — so the switch has nothing to swap in the first place, on or off, the same way Reduce Transparency has nothing to flatten in a keyboard whose themes never used translucency. None of this touches Full Access, which Kibo reads only for the Copy word, Copy line and Paste buttons on its own toolbar. It is free to download.
Frequently asked questions
Does turning on Bold Text change how my custom keyboard’s letters look?
Only if that keyboard’s own code checks for the setting and reacts to it. A third-party keyboard draws its key labels itself rather than through the system text layer Bold Text reaches, so a keyboard with a fixed label weight looks identical with the switch on or off.
Where do I find Bold Text?
Settings → Accessibility → Display & Text Size → Bold Text — the same screen as Reduce Transparency, Reduce Motion and Larger Text.
Is Bold Text the same as Larger Text?
No. Larger Text scales the size of text through Dynamic Type, something each app has to opt into individually. Bold Text is a separate trait that only changes stroke weight, and the two toggle independently of each other.
Why do the letters on Apple’s keyboard get bolder but mine do not?
Apple’s keyboard draws its key labels through the same system text-rendering its other apps use, so the system-wide switch reaches them directly. A custom keyboard draws its own labels independently of that layer, so the same switch only affects it if the keyboard’s developer wired it in.
Try it on your own keyboard
Kibo is a free custom keyboard for iPhone with real mechanical key sounds, a wardrobe of themes and RGB backlight effects. No account, no ads, and it works with Full Access left off.