Why the 100-Byte Limit is a Byte Limit, Not a Character Limit
In App Store Connect, the keywords field has a strict limit of 100 bytes (UTF-8).
For Latin ASCII characters (a-z), each character is exactly 1 byte.
However, for Cyrillic (а-я), Greek, Arabic, and accented Latin characters, each character takes 2 bytes.
Emoji and CJK characters take 3 to 4 bytes each!
If you input 60 Cyrillic characters in App Store Connect, you will receive an immediate submission error:
"The keyword string exceeds the maximum byte limit of 100 bytes."
Keyword Cannibalization Mechanics
Apple indexes words across your Title (30 chars), Subtitle (30 chars), and Keywords (100 bytes) into a single unified search index.
Repeating a word from your title inside the keywords field gives zero additional search ranking power and wastes precious bytes.
- Title: Cosmo Color Sort: Water Puzzle
- ❌ Keywords:
water,sort,puzzle,relaxing,liquid(Wastes 17 bytes on duplicate words!) - ✅ Keywords:
relaxing,liquid,zen,brain,pour,tubes(100% net-new indexing reach)
The 3 Golden Rules of Keyword Packing
1. Single Commas with Zero Spaces
App Store Connect uses commas as separators. Spaces after commas are counted against your 100-byte allowance:
- ❌
relaxing, liquid, zen(19 bytes) - ✅
relaxing,liquid,zen(17 bytes — saves 2 bytes for another search term)
2. Never Repeat Plurals or Singulars
Apple's search engine automatically combines singular and plural forms for English keywords. Targeting both game and games is redundant.
3. Exploit Cross-Localization Keyword Sharing
In secondary localizations (e.g. UK English in the US storefront or Spanish in North America), the keyword fields combine to provide additional search indexation.
Cyrillic & Non-Latin Byte Costs
| Script / Character Type | Bytes per Character | Max Chars in 100b (approx) | Example |
|---|---|---|---|
| Latin ASCII (a-z, 0-9) | 1 byte | ~85–90 chars + commas | puzzle,match,color |
| Cyrillic (а-я, і, ї, є) | 2 bytes | ~40–45 chars + commas | головоломка,релакс |
| Accented Latin (é, ü, ñ) | 2 bytes | ~45–50 chars + commas | café,español |
| CJK (Chinese, Japanese, Korean) | 3 bytes | ~28–30 chars + commas | ゲーム,パズル |
| Emoji (🔥, 🚀, 💡) | 4 bytes | ~20–22 emojis | 🔥,⚡️,🎮 (Never use in keywords!) |
The 100-Byte Packing Checklist
- Write out your candidate keyword list sorted by search volume.
- Remove any words that already appear in your 30-char Title or 30-char Subtitle.
- Remove stop words (
the,and,for,with) and punctuation other than commas. - Eliminate spaces adjacent to commas.
- Verify total UTF-8 byte count equals exactly 98–100 bytes using the Larko Keyword Packer.
