How to add text to a PDF on iPhone

Somebody sent you a PDF and you need to put words on it. Your name on the top line. An address in the middle of a paragraph. A note in the margin that says “approved, see attached”. Nothing complicated — you just need text on the page, and you’d rather not open a laptop to do it.

Your iPhone can already do this. It has done since iOS 11, the tool is free, and most people have never found it because it’s hidden behind an icon that looks like a pen tip.

First, the distinction nobody makes

There are two completely different jobs hiding inside “add text to a PDF”, and almost every page you’ll find on this topic blurs them together:

What you want	What it really is	Can an iPhone do it?
Put new words on the page — your name, a date, a note	Annotation: text sits on top of the page	Yes, free, in about a minute
Change words that are already printed in the document	Editing: rewriting the PDF’s own content	Not really — that needs a desktop PDF editor

This page is about the first one, which is what people almost always mean. If you’re trying to correct a typo inside somebody else’s paragraph, no iPhone signing or annotation tool will do that cleanly — you need the original document, or a proper PDF editor on a computer. Anyone telling you otherwise on a phone is selling you a text box placed over the top of the old words, which looks exactly as bodged as it sounds when the document is printed.

The free way: iOS Markup

Nothing to install, nothing to sign up for.

Open the PDF in Files (or tap the attachment in Mail).
Tap the Markup icon — the pen tip inside a circle, top right.
Tap the + button (bottom right) → Text.
A small box saying “Text” lands in the middle of the page. Tap it once → Edit → type what you want.
Tap outside to finish, then drag the box where it belongs.
Tap the box → Aa to change size, font and alignment; the coloured dots set the ink colour.
Repeat for each piece of text. Tap Done, then Share to send the file on.

That’s the whole answer for a one-off, and you should stop reading here if that’s what you have. It’s free, it’s already on your phone, and what comes out the other end is a normal PDF anyone can open.

Four things that make Markup text look right

Most “typed on a PDF” text looks obviously typed on. It doesn’t have to.

Zoom in before you place anything. Pinch until the line you’re filling fills the screen. Placement accuracy on glass is entirely a function of how big the target is.
Set the size once, on the first box. Markup remembers it for the next box, so if you get box one right, boxes two through nine come out matching. Fix the size after placing five boxes and you’ll be resizing five boxes.
Use black, or the dark blue. Those read as pen. The reds and greens read as “somebody edited this PDF”.
Left-align, then drag. The Aa panel has alignment controls; a left-aligned box dragged to the start of a line sits far straighter than a centred box nudged by eye.

Where Markup starts to hurt

Being honest about it, because the vendor pages on this topic never are:

Every box is placed and sized by hand. A form with twelve blanks is twelve rounds of tap-drag-pinch-squint.
Nothing is remembered between documents. Your name, your address, your email — retyped from scratch every single time.
The font choice is limited and there’s no way to match the document’s own typeface, so added text rarely looks native.
Boxes can be nudged accidentally while you’re scrolling, and you won’t always notice before you hit Share.

For one PDF a year, none of that matters. For one a week, all of it does.

If the PDF has real form fields, stop and read this instead

Tap a blank line in the document. If a keyboard pops up and a cursor appears, the PDF has interactive form fields — it’s a real fillable form, and you should be typing into the fields rather than floating text boxes over them. That’s a different job with a better answer: how to fill out and sign a form on iPhone covers it properly, including checkboxes and dates.

If tapping does nothing at all, the document is flat — a scan, or something exported without fields — and this page is the right one. (There are a couple of other reasons a PDF can refuse your taps, like permission restrictions or encryption: why can’t I type in a PDF on my iPhone walks through all four.)

The app route, if this is a regular thing

Signed exists for the repeat case rather than the one-off. You import the PDF, then drop the pieces you need — text, your name, the date, initials, a checkmark, your signature — and export a clean flattened copy.

The difference isn’t that it can do something Markup can’t on any single document. It’s that the parts that don’t change get saved once and reused: your name and initials are a tap on document twenty just as they were on document two, and the date drops in already filled instead of being typed character by character. Text elements land at a consistent size instead of drifting.

And the document never leaves your iPhone — no upload, no account, no cloud copy of a page with your address on it. That matters more than it sounds like it does when the thing you’re annotating is a bank letter.

To be straight about the limits: Signed adds and places text, it does not rewrite the PDF’s existing words. Neither does Markup. That job belongs to a desktop editor.

One thing to know before you export

While the file is still open in Markup — or still a working document in an app — your text boxes are annotations. They can be tapped, moved, edited, deleted.

Once you export or flatten the file, the text is baked into the page. Nobody can nudge it out of place, which is the point, but you can’t edit it either — a change means going back to the original PDF and starting again. So proofread before you export, not after, and if something’s already wrong, here’s how to delete text you added to a PDF on iPhone while you still can. If you want the detail on what flattening actually does and why it’s usually the right call before sending a document on, that’s how to flatten a signed PDF on iPhone.

Worth knowing too: a text box placed over existing words covers them, it doesn’t remove them. The original text is still in the file underneath, and it’s still selectable and searchable in some viewers. Never use a white box as a way to hide information you don’t want the recipient to see — that isn’t redaction, and it has embarrassed better-resourced people than us.

The short version

Free, one-off: Files → Markup (pen icon) → + → Text → type, drag, size. Done.
Zoom in first, get box one right, and the rest follow.
Keyboard appears when you tap a blank? It’s a real form — use the form guide instead.
Doing this weekly? Saved, reusable text is the entire argument for an app; a single document isn’t.
Editing words already printed in the document isn’t a phone job at all.