If you make videos in Bangla, Hindi, Arabic, Urdu, Thai, Chinese, Japanese or Korean, you have probably seen it: you type a title, pick a punchy font, and the text comes out as empty boxes, letters that should join sitting apart, or a conjunct split into pieces. Nothing is wrong with your text. The font simply was not built for your script.

The fix is to use a font that was, and an editor that lets you bring it in. This guide covers both: why the default fails, where to get a font you are allowed to use, how to check it covers your language, and how to add it to Zella's titles and captions on Mac and iPhone.

Why the default font breaks your language

A font is a set of drawings plus rules. The drawings are glyphs. The rules say how glyphs combine, and complex scripts depend on them:

  • Conjuncts (Bangla, Devanagari). ক্ষ, স্ত্র, क्ष and श्र are not two letters placed side by side. The font has to carry a combined shape and the rule that triggers it. Without them you get the parts with a visible hasanta or halant, which reads as a spelling mistake.
  • Joining (Arabic, Urdu). Each Arabic letter has up to four forms depending on its neighbours. A font without those forms prints every letter in isolation, and the word becomes unreadable.
  • Right to left. Arabic and Urdu run right to left, with numbers and Latin words running left to right inside them. The text engine handles the order, but only if the font supplies the glyphs.
  • Stacked marks (Thai, Vietnamese). Thai tone marks sit above vowel marks, and Vietnamese letters carry two diacritics at once (ặ, ỗ). A font that lacks the positioning data collides them or drops them.
  • Sheer size (Chinese, Japanese, Korean). A usable CJK font covers thousands of characters, so most stylish Latin fonts include none at all.

The popular caption faces, the heavy condensed sans and the rounded display fonts, are Latin only. When you force one onto another script, the system swaps in a fallback for each missing character. At best that is a font nobody chose. At worst it is a mix of two fonts in one word, or the empty rectangles typographers call tofu.

A video frame with captions burned in, one word highlighted as it is spoken.

Where to get a font you are allowed to use

Two rules: get the font from its publisher, and read the licence.

Google Fonts is the easiest start. Every family there is free, and most use the SIL Open Font License, which allows use in videos, including commercial ones. Use the language filter to list only fonts that support your script. Good starting points:

  • Bangla: Noto Sans Bengali, Hind Siliguri, Anek Bangla, Tiro Bangla
  • Hindi and other Devanagari: Noto Sans Devanagari, Mukta, Hind, Tiro Devanagari Hindi
  • Arabic (Naskh and Kufi): Noto Naskh Arabic, Noto Kufi Arabic, Cairo, Tajawal, Amiri
  • Urdu (Nastaliq): Noto Nastaliq Urdu
  • Thai: Noto Sans Thai, Sarabun, Kanit, Prompt
  • Chinese (Simplified): Noto Sans SC, Noto Serif SC, ZCOOL KuaiLe
  • Japanese and Korean: Noto Sans JP, M PLUS 1p, Noto Sans KR, Black Han Sans
  • Vietnamese: Be Vietnam Pro, or any family whose language list includes Vietnamese

Noto is Google's family built to cover every script in Unicode, in matching styles. If you need one look across several languages in the same video, Noto is the safe answer.

A brand font you bought is fine too, as long as its licence covers video. Some desktop licences cover print and screen work but treat burned-in video or broadcast as a separate tier, so check before a paid campaign. Avoid "free font" mirror sites: the files are often renamed copies with no licence, and sometimes damaged.

How to check a font covers your script

The language filter is a start, not proof. Before you commit a whole video to a font:

  1. Type your own sentence into the font's preview, not the sample text. Use real words from your script.
  2. Include the hard cases. For Bangla, a few conjuncts such as ক্ষ্ম, ন্দ্র and স্ত্র. For Hindi, क्ष, द्ध and श्र. For Arabic, a long joined word. For Thai, a syllable with a tone mark over a vowel mark. For Vietnamese, letters with two marks.
  3. Check every weight you plan to use. Some families cover a script in Regular and Bold only.
  4. Check the Latin too. If your titles mix in English words or numbers, make sure the font has them, or accept that those characters will fall back to another font.

Zella helps here: an imported font that has no Latin letters shows a sample of its own script on its card in the font picker instead of "Aa", so you can tell at a glance which script a face is for.

File formats that work

Zella imports .ttf (TrueType), .otf (OpenType), .ttc and .otc (collections that hold several faces in one file, common for CJK). Up to 160 MB per file, which covers full CJK families.

Web fonts (WOFF and WOFF2) are not on that list. Download the desktop files instead: on Google Fonts the download button gives you TTF files.

A variable font is one file that holds a whole weight range, and it imports as one face. If you want specific named weights (Light, SemiBold, Black) to pick from, import the static files that usually come in the same download, in a folder named static.

How to add a font on Mac

Titles and captions share one font library, so a font you add in one place appears in the other.

For titles:

  1. Open the Titles tab and select a title, or start a new one.
  2. In the Font row, click Add font, or click the Add font card at the start of the My fonts section of the grid. You can also drag font files from Finder straight onto the font grid.
  3. Choose one or more files. Zella confirms with a line such as "Added Hind Siliguri." and selects the new family.
  4. Use the Weight menu to pick a style. For an imported family it lists that family's own styles, not a generic set.

Right-click a card to Save as favourite, or to Remove from My fonts.

For captions: open the Captions tab, open the Font menu and choose Add Font… (.ttf / .otf / .ttc). Imported faces appear at the top of that menu under My Fonts.

Under the title font grid the app reminds you: "Only use fonts you have the right to use." That is the licence point above, in one line.

How to add a font on iPhone

  1. In the editor, tap Captions or Text in the tool strip.
  2. Find the font picker: the Font section on the Captions tab, or Font & size for titles.
  3. Tap the Add font card at the start of the grid. Files opens.
  4. Pick one or more font files from iCloud Drive, On My iPhone or any connected storage. The first new font is applied to the caption or title you opened the picker from.
  5. From then on, the My fonts chip filters the grid to your imported fonts.

On the phone each style is its own card, so a family with four weights shows four cards. Long-press a card to Save as favourite or Remove from My fonts. The line under the grid reads: "Add .ttf, .otf, .ttc or .otc files from Files. Only use fonts you have the right to use."

The built-in fonts and the favourites row are covered in how to change the caption font on iPhone. This guide is about the fonts you bring yourself.

Captions or titles: which to use for your script

Both use the same imported fonts, but they get their text differently, and that matters for some languages.

Titles are text you type. They work in any script your font covers, including Bangla, Urdu and every script above. For a hook line, a name, a quote or a chapter card, a title in a good font is the most reliable result. Titles also take Zella's text animations. With joined scripts such as Arabic, preview a per-letter animation before you export, and switch to per word or per line if it looks wrong.

Captions start from transcription, and on-device transcription does not cover every language equally. Zella does not offer Bengali transcription as working on-device, and says so when you pick it. If you already have a subtitle file, import the SRT and style it with your font. On iPhone you can also speak Bangla and turn on English captions, covered in captions on iPhone. For languages that do transcribe on-device, such as Hindi, Arabic, Thai, Chinese, Japanese and Korean, the captions come out in their own script and your imported font applies directly. Details per language are in the captions guide.

One behaviour worth knowing: the built-in caption faces are Latin only, so on a non-Latin transcript Zella falls back to the system face rather than draw broken text. Imported fonts are exempt from that rule. A Bangla or Arabic font you imported for that script is the one that renders.

Moving a project to the Mac, fonts included

Fonts usually get lost when a project moves between devices. Zella packs them.

On iPhone, open Export, go to Continue on Mac and tap Save project to Files. The .zella project includes the imported fonts its titles and captions use, and the Mac adds them to its own library when you open the project. Another iPhone does the same. The full hand-off is in export and Mac hand-off.

If a project ever opens without a font it needs, Zella names it and shows the default font in its place, with a pointer to Titles > Font > Add font on the Mac (or Text > Font > Add font on iPhone). Add the file and the text renders as designed.

Where your fonts live

An imported font is checked first: a file that is damaged or is not a real font is refused with a plain message, before anything is copied. A good file is copied into Zella's own library, registered for Zella only (nothing is installed system-wide, and other apps do not see it), and registered again at every launch, so a project keeps rendering after a restart. Nothing is uploaded. For more on the feature itself, see the custom fonts docs.

Troubleshooting

The text shows boxes. The font lacks those characters. Check the font's language support, and make sure you selected the imported font rather than a built-in display face.

Conjuncts are split or Arabic letters do not join. The font has the letters but not the rules for combining them, which happens with old or converted fonts. Use a current version from the publisher, such as the Noto or Google Fonts release.

Only one weight shows up. You imported a variable font, or only one file from the family. Import the static files for each weight you want.

"is not a font file" means the file is not one of the four supported types, often a WOFF web font or a zip you have not unpacked. Unzip it and pick the .ttf or .otf inside.

"was already in My fonts" means that exact file is already imported. Nothing is duplicated.

A removed font changed my text. Removing a font affects the text that used it: on Mac, titles show Helvetica Neue, and on iPhone, titles and captions show the system font, until you add the font again.

Frequently asked questions

Which font formats can I import? .ttf, .otf, .ttc and .otc. Web fonts (WOFF, WOFF2) are not supported, so download the desktop files.

Do custom fonts work for Bangla, Hindi and Arabic? Yes. The app shapes Bangla and Devanagari conjuncts, Arabic joining and right-to-left text from the font's own rules, so a font built for the script renders correctly in titles and captions.

Can I get Bangla captions automatically from speech? No. Zella does not offer Bengali transcription as working on-device. Use titles for Bangla text, import an SRT you already have, or on iPhone use English captions.

Do I need Pro to import fonts? No. Font import is part of the editor on both apps.

Are my fonts uploaded anywhere? No. They are copied into Zella's library on your device and registered for Zella only.

Will my fonts be there when I open an iPhone project on the Mac? Yes, when you save the project with Save project to Files. The .zella file carries the imported fonts its titles and captions use, and the Mac adds them when it opens the project.

Where can I find free fonts for my language? Google Fonts, filtered by language, and the Noto family. Both are free and licensed for use in video.