How to fill out a PDF in Chinese, Japanese or Korean on iPhone

Typing your name in Hangul, an address in Chinese or a reply in Japanese into a PDF on your iPhone usually looks fine on screen. The problem tends to show up later, when the person you sent it to opens the file, or when it gets printed, and your text comes out as empty boxes, question marks or nothing at all.

That gap between what you see and what they get is the whole story here. Below: how to type the characters in the first place, why they sometimes don’t survive, and the ten-second check that tells you before you hit send.

Step 1: add the keyboard

If you haven’t already, iOS needs the right keyboard before any app can take Chinese, Japanese or Korean input:

1. Open Settings › General › Keyboard › Keyboards.
2. Tap Add New Keyboard… and choose Chinese (Simplified or Traditional, then Pinyin, Stroke, Handwriting or another input method), Japanese (Kana or Romaji) or Korean.
3. In any text box, tap the globe or the 🌐 key to switch to it.

This part is the same in every app. Once the keyboard is there, the question is only whether the PDF tool keeps the characters when it saves the file.

The free option: iOS Markup

For a short form, try the tool you already have. Open the PDF in Files or Mail, tap the pen icon to start Markup, then tap + › Text, double-tap the text box and type with your new keyboard. There’s a full walkthrough in how to add text to a PDF on iPhone.

Markup puts your text on top of the page as an annotation. Whether those characters display correctly in someone else’s PDF viewer depends on how the file is saved and what that viewer does with it, so don’t take the screen in Markup as proof. Do the check in the section below. If your characters come through, Markup is all you need.

Why characters turn into boxes

The boxes (some people call them “tofu”) mean the app showing the PDF has the character codes but no shape to draw them with. Text in a PDF is stored as references into a font. If the font the text points to doesn’t contain Chinese, Japanese or Korean glyphs, and it isn’t embedded in the file, the viewer has nothing to draw. Some viewers quietly substitute a font that has the characters. Others don’t, and that’s when your name disappears on the other end.

Your iPhone itself has full Chinese, Japanese and Korean fonts built in, which is why everything looks right while you’re editing. The file you send has to carry its own copy.

The form-field trap

If you tap a box on the PDF and the keyboard comes up straight away, the PDF is a fillable form, and each field has its own font, chosen by whoever made the form. A lot of forms are built with a Latin-only font such as Helvetica or Times. That’s fine for English. For Hangul or kanji, the field’s font simply has no characters to offer.

This is exactly the situation in the Adobe forum threads where people can’t type Chinese into a form, or where the text turns into boxes after saving. You can’t change a field’s font on an iPhone, and the app filling the form may or may not work around it.

Your realistic options:

1. Use the Latin-script version if the form allows it (romanised name, English address). For many official forms that’s what the recipient expects anyway.
2. Leave the field empty and put your text on top of the page as a separate text box, in a tool that embeds a suitable font. On paper it looks the same. It just isn’t stored inside the form field, which only matters if someone plans to extract the answers automatically.

If tapping the box does nothing at all, the PDF has no fields, and why can’t I type in a PDF on my iPhone covers that case. Text on top of the page is the fix there too.

Always check the exported file

Whatever app you use, this is the step that matters:

1. Export or share the finished PDF (save it to Files is fine).
2. Open that copy in a different app from the one you edited in, such as Files’ preview or Books. If you can, open it on a computer as well.
3. Zoom into your text. If every character is there, the recipient will see them too.

It takes ten seconds and it’s the only reliable way to know. An editor showing your text proves your phone has the font, not that the file does.

Filling the PDF in Signed

If you fill forms in Korean, Chinese or Japanese regularly, Signed handles the font part for you. Its Text, Name, Initials and Date fields print Korean, Chinese and Japanese characters through the scripts’ system fonts, and the exported PDF embeds the face that was used, so the copy you send carries its own font. That behaviour is covered by an automated test in the app, so it doesn’t quietly break in an update.

A few practical details:

• Signed places its text on top of the page instead of typing into the form’s own field, so a Latin-only field font doesn’t get in the way.
• You can pick a different font for each field from every family on the phone, or import your own TTF or OTF file. If you choose a font for a Latin script, pick one that also covers your characters, and run the export check above.
• On export, Signed flattens your text into a copy of the page, so the recipient’s viewer has nothing to substitute.
• The app’s menus are in English and a few European languages, not in Chinese, Japanese or Korean. What you type into documents can be in any of them.
• It’s a paid app. For one form, once, Markup plus the export check is the cheaper answer.

Your documents stay on your iPhone. Nothing is uploaded.

Quick answers

Why does my Chinese text show as boxes in a PDF? The font the text uses either has no Chinese characters or isn’t embedded in the file, so the viewer can’t draw them. Put the text in with a tool that embeds a font covering the script, then check the exported copy in another app.

Can I sign a PDF with my name in Korean or Japanese? Yes, as text or as a drawn signature. A drawn signature is an image, so the script doesn’t matter to the file. If you’d rather sign by hand, see how to sign a PDF without printing it. Whether the recipient accepts a signature in a particular script is up to them and the document.

Can I change the font of a fillable form field on iPhone? No. The field’s font is set inside the PDF by whoever made it. Put your text on top of the page instead, or use the Latin-script version the form expects.