How to Edit a PDF on iPhone: Preview, Markup and a Free Browser Option

What we tested and what we did not

We ran our tools in WebKit, the engine family Safari uses, on a Windows PC at iPhone screen size (390 pixels wide). In that setup we changed text, added a text box, signed, filled a form, redacted and deleted pages, then checked each saved file. Finger gestures were simulated by a script. We have not run these tools on a physical iPhone.

That gap matters. WebKit on a PC doesn't show iOS memory limits, the iOS file picker or how a download lands in the Files app, so we can't describe those from our own runs. Treat every step in the browser sections as something to confirm on your phone with a short file, and open the saved PDF before you send it to anyone.

What Apple's tools can do, and where the guides stop

Apple's iPhone User Guide covers two sets of tools for PDFs. Markup works in supported apps, and Apple names Notes and Photos as examples. The Preview app has its own chapter, which Apple lists for iOS 26 and iOS 27. Preview fills and signs forms, adds text, shapes and stickers, highlights text, and adds, deletes, rotates, reorders or crops pages. If your iPhone runs an older version, the Preview steps below may not apply.

The line that matters is between adding to a page and changing what is on it. Apple's guides explain how to place new text, a signature or a highlight. The pages we read don't describe a way to retype or delete words already in the PDF. So if a contract has the wrong date, a text box over it is a patch, and the old date may still be underneath.

How to sign or add text in Apple's Preview

If you only need to fill in, sign or mark up a document, start here. These are Apple's steps in short form. We haven't run them ourselves.

1. Open the PDF in the Preview app.
2. To fill a form, tap the Form Filling button, tap a field and enter your text, or tap an AutoFill suggestion above the keyboard.
3. To sign or add text beyond the blank fields, tap the add button, then choose Add Signature or Add Text Form Box.
4. Sign with your finger, or type your text, then drag it where you want it.
5. To add a highlight, select the text and tap Highlight. To add a shape or sticker, tap the Markup button, then the add button.

To delete a page, Apple says to show the thumbnails in Preview, touch and hold a thumbnail, and tap Delete Page. The same menu inserts a blank page or another file.

How to change existing text in a mobile browser

When you need to fix a wrong number or a typo, covering the old words with a box and typing over it looks messy. The new font rarely matches, and the old text can stay in the file where a copy command still finds it.

A cleaner way is to replace the line where it sits. Edit PDF does this inside your browser tab, so the file isn't sent to a server. These steps come from our touch test in WebKit at iPhone size.

1. Open Edit PDF in your browser and choose your file.
2. Tap once on the line you want to change. The first tap selects it.
3. Tap Edit selected text.
4. Type your correction, then press return or tap outside the box.
5. Tap Download to save the updated PDF.

If the blank you're completing isn't a real form field, our tutorial on how to type on a PDF covers placing text boxes neatly. To turn blank lines into fields other people can fill in, see how to make a PDF fillable.

Forms, signatures and pages in the browser

Preview may be all you need for these jobs. The browser tools are useful when you don't have Preview, or when you want the same steps on a phone and a laptop.

• Forms: Fill Form lets you type into a PDF's fields and download the filled copy.
• Signatures: Sign PDF lets you draw a signature, tap to place it, and drag it into position.
• Pages: Delete PDF Pages removes the pages you list by number.
• Private details: Redact PDF lets you drag a black box over text and removes what's under it by turning that page into an image.
• Other devices: if you also work on a computer, see how to edit a PDF on Mac and our overview of every way to edit a PDF.

When a browser is not the right fit

A browser tool suits a quick correction. It isn't the best choice for everything, and an honest guide should say so.

If you edit long documents on your phone every day, a dedicated app or a computer will feel better than any website. Small screens make long reading tiring whichever tool you use.

Big rewrites need a word processor. A PDF fixes letters at set positions on the page, so if you delete two sentences from a paragraph, the lines below won't move up to close the gap. When a document needs that kind of change, edit the original Word or Pages file and export a new PDF.

Big files on a phone

Our browser tools do all the work on your device, so your phone's memory sets the limit. Big files may be slow, and a browser tab can reload or fail if it runs out of memory. We haven't measured where that happens on a real iPhone, so we can't give you a safe page count or file size.

Scans, photos and detailed artwork use far more memory per page than plain text. Try a short file first. If a large PDF won't open or the tab reloads, use a laptop or desktop for that file, or delete the pages you don't need on a computer first.

Which option should you pick on an iPhone?

• Filling a form, signing or adding a note: start with Preview.
• Removing or reordering pages: Preview can do both.
• Fixing a wrong date, price or name: try Edit PDF in your browser.
• Hiding private details: use Redact PDF, then check the saved file.
• Rewriting whole paragraphs: go back to the Word or Pages original.

Frequently asked questions