Why does my iPhone change straight quotes to curly quotes?
Smart Punctuation quietly swaps your quotes and a double hyphen for their typographic versions as you type. What it changes, why iOS does it, where it causes real trouble, and the single switch that stops it.
You type an apostrophe and get a slanted one back. You type a quotation mark and the opening and closing marks curl in opposite directions, as though the keyboard decided which end of the sentence you were on. Nothing on the keyboard offers a choice between the two shapes, so the substitution can look like a glitch or like autocorrect wandering out of its lane. It is neither. It is a separate iOS feature called Smart Punctuation, it is on by default, and it has its own switch.
What Smart Punctuation actually changes
It works on the character you just typed, in the moment you type it, in any app using the standard text field.
- The straight apostrophe (') becomes a curled one, leaning the way a printed apostrophe does in a word like it’s.
- The straight double quote (") becomes a matched pair: one shape when it opens a quotation, the mirrored shape when it closes it. iOS works out which is which from what is around the cursor.
- Two hyphens typed in a row (--) become a single long dash.
- The shapes themselves depend on the keyboard’s language, not on you — several languages use quotation marks that look nothing like the English pair, and a keyboard for one of those languages produces its own convention instead.
Why iOS does this at all
The straight quote is an artefact of the mechanical typewriter. There was no room on the type basket for four separate quotation marks and two apostrophes, so one vertical stroke was made to stand in for all of them, and computer keyboards inherited that compromise unchanged. Typesetting never used it: printed books have always used the curled marks, because they show at a glance whether a quotation is opening or closing.
Smart Punctuation exists to put the printed shapes back without asking you to hunt for them. For ordinary writing — a message, an email, a caption — it is a small, invisible improvement, which is exactly why most people never notice it until the day it gets in the way.
Where it causes real trouble
A curly quote is not a decorated version of a straight quote. It is a different character with a different code point, and anything comparing text exactly will treat the two as unrelated. That is fine in a sentence and a problem everywhere else.
- Code and terminal commands. A shell, a script or a JSON file expects the straight character. Paste in a line where the quotes were curled on the way through and it fails to parse, usually with an error that says nothing about quotation marks.
- Spreadsheet formulas, which use the straight double quote to delimit text and reject the curled one.
- Exact-match searching. Looking for a phrase containing an apostrophe can come up empty when the stored text used one shape and your search used the other.
- Anything that will later be compared, deduplicated or looked up as a string — reference codes, identifiers, saved queries.
The double hyphen has the same edge. Typing -- as a command-line flag prefix and getting a single long dash back turns a valid option into something the command has never heard of.
Turning it off
- Open Settings → General → Keyboard.
- Find the switch labelled Smart Punctuation.
- Turn it off.
It applies immediately and system-wide to Apple’s own keyboard, in every app. From then on the character you type is the character you get, in both shapes and in the double hyphen.
Text you already typed does not change back
The switch governs what happens at the moment of typing, so it has no effect on anything already sitting in a note, a document or a message. Those characters were converted when they were entered and they stay converted. Retyping the character with the switch off, or a find-and-replace in whichever app holds the text, is the only way back for existing text.
Getting the shapes deliberately once it is off
Turning Smart Punctuation off does not put the curly marks out of reach. On the numbers page, pressing and holding the apostrophe or the quote key brings up a short row of variants that includes the curled pair, along with the quote styles used in other languages — the same long-press gesture covered in the guide on currency and special symbols. The hyphen key holds the en dash and em dash the same way. So the switch is less a choice between two sets of characters than a choice about which one arrives without being asked for.
Why some apps never do it, switch on or off
Open a code editor, an SSH client or a terminal app on the same phone and the quotes usually stay straight even with Smart Punctuation switched on. That is deliberate on the app’s part rather than a difference in your settings. A text field can be marked by the app that owns it as one where the substitution should not happen, and iOS honours that mark for that field alone. It is the same mechanism that lets an app say a field holds an email address or a password, and it is why the behaviour can differ from one screen to the next inside a single phone.
Third-party keyboards and this switch
Smart Punctuation is read by Apple’s own keyboard. A keyboard you add from the App Store is separate code that decides for itself what a key press inserts, so the substitution is something it has to implement or not — it does not inherit it from that Settings screen. In practice this means switching to a third-party keyboard can quietly stop the conversion happening, which is a relief if you write code on your phone and a surprise if you had come to rely on the curled marks appearing on their own.
Nothing is wrong in either case, and no keyboard can be blamed for it. iOS hands a keyboard extension the field and the taps, not Apple’s typing behaviour.
Where Kibo fits
Kibo is a free custom iPhone keyboard built around mechanical key sounds, themes and backlight effects. One detail is relevant here: its 12 fancy text styles convert letters only — numbers, punctuation and emoji pass through untouched — so whichever quote shape ended up in your text stays exactly the shape it was. Full Access can stay off; the only thing Kibo reads it for is the Copy word, Copy line and Paste buttons on its own toolbar.
Frequently asked questions
How do I stop my iPhone from changing straight quotes to curly quotes?
Settings → General → Keyboard → Smart Punctuation, turned off. The change applies immediately to Apple’s keyboard in every app, and from then on the character you type is the one that appears.
Is Smart Punctuation the same thing as autocorrect?
No. They are separate switches on the same Settings screen and they do different jobs. Auto-Correction replaces whole words it thinks you mistyped; Smart Punctuation only swaps quotation marks, apostrophes and a double hyphen for their typographic equivalents. Turning off one leaves the other exactly as it was.
Why does my code break when I paste it from my iPhone?
Most often because the quotes were curled on the way in. A curly quote is a different character from the straight one a shell or a parser expects, so the line fails even though it looks correct. Turning off Smart Punctuation stops it happening to anything you type from that point on.
Does turning off Smart Punctuation remove the curly quotes already in my notes?
No. The switch only affects what happens as you type. Characters already in a document stay as they were, so existing text needs retyping or a find-and-replace in whichever app holds it.
Why do my quotes stay straight on a third-party keyboard?
Because that keyboard has to implement the substitution itself — the Smart Punctuation switch in Settings is read by Apple’s keyboard, not shared automatically with every keyboard extension.
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.