How to Fill Out a PDF on iPhone

How do I fill out a PDF form on my iPhone?

Open Fill PDF in Safari and tap Choose a PDF form to pick it from your files. Tap Fill the fields as a list and type each answer in its full-size box, tick checkboxes and choose options from the lists. Then tap Save filled PDF and Download; the original stays as it was.

1. Open Safari and go to Fill PDF.
2. Tap Choose a PDF form and pick it from your files.
3. Use Fill the fields as a list to type each answer in a full-size box.
4. Tap Save filled PDF, then Download.

The filled copy lands where Safari keeps downloads: the Downloads folder in iCloud Drive, in the Files app, unless you changed it in Settings, Apps, Safari.

Why are the form boxes so small on my phone?

A PDF page is drawn to fit the phone's width, so everything on it shrinks, form boxes included. On a 375-pixel-wide screen, our test form's boxes were 9 to 12 pixels tall, too small for a finger. That is why Fill PDF also shows each field as a 44-pixel box in a list, open by default on phones.

Typing in the list fills the box on the page at the same moment, and typing on the page fills the list, so you can switch between them. In our test, all 8 fields (text, checkbox, list) were saved correctly in the downloaded PDF.

This site's production build in Chrome 152 set to a 375 x 812 phone screen on a laptop (i5-8350U), not on a real iPhone, 2026-10-12.

What if the PDF has no fillable fields?

Some forms are just pictures of paper forms, with lines but no fields. Fill PDF says so and lets you type anywhere: choose Text, Check or Date, then tap the page where the answer goes and type. If you want fields that others can fill too, Create Fillable PDF adds real form fields to a plain PDF.

Try Create Fillable PDF for that.

A scanned form works the same way. To make its printed text searchable as well, run it through OCR PDF first.

How do I sign the form on my iPhone?

Fill the form first and download it, then open Sign PDF and choose the filled copy. Draw your signature with your finger, type it, or use a picture of it, place it on the page and download again. If the form needs a certificate signature rather than a drawn one, use Digital Signature PDF with your own certificate file.

Our guide Electronic vs Digital Signature explains which kind a form usually needs.

How do I stop my answers being changed?

Before saving, tick Lock the answers (flatten) in Fill PDF. That turns the filled fields into part of the page, so the next person sees your answers but cannot edit them, and every PDF reader shows them the same way. Keep an unlocked copy if you might need to change an answer later, because locking cannot be undone.

You can also lock a form after filling it with Flatten PDF.