Chinese smartphone brands have often found themselves in hot water over restrictions on what you can do or tap on them, thanks to built-in text filtering and system-level censorship features. Even third-party apps like LINE have had to follow these censorship rules and block hundreds of words and phrases that are considered sensitive or offensive in China, even if they are perfectly normal elsewhere.
It seems that Apple also maintains such a list of filtered words, and tens of thousands of them are baked into its iPhone keyboard at the system level. However, these words and phrases are not immediately blocked. You can still type them, but the autocomplete and swipe-typing systems automatically ignore them, so they never appear among the suggested words above the keyboard.
What exactly is Apple hiding in its iPhone keyboard?
Independent researcher Derik Kauffman detailed the discovery (via Swipe Blocked). A majority of the words are the usual suspects, related to violence, drugs, and overtly sexual themes. But some other things will raise censorship concerns. For example, phrases like “dictator Trump” and “sleepy Joe,” both used widely in public political commentary, are on the keyboard’s gray list.
In a statement shared with Reuters, Apple did not offer a detailed explanation and only said that the iPhone’s built-in keyboard is designed to avoid words that may be offensive or inappropriate.
But this strange behavior is not limited to words or topics related to the United States. The predictive writing system on the iOS keyboard also blocks terms such as “Tibetan independence” and “United Ireland,” as well as phrases mocking politicians, including Indian Prime Minister Narendra Modi and leader of the opposition Rahul Gandhi. Kauffman says that every major language supported by the iOS keyboard has a version of this invisible gray list that Apple has never released publicly.
How did researchers discover Apple’s hidden word list?
Kauffman says he first suspected such a gray list existed when he tried to swipe phrases like “bad boy” and “white man.” He then used OpenAI’s Codex and Anthropic’s Claude Code to dig into iOS, eventually discovering thousands of words and phrases on the gray list.
Reuters’ own tests found that when you try to swipe “Tibetan independence” and “United Ireland,” the keyboard often changes it to “Tibetan independence” and “United Iceland.” Also, typing “white man” means “white”, while “red man” and “blue man” come through without a problem.
The discovery is surprising, although not entirely shocking. In recent years, users have reported scattered cases of typing a word, only for the predictive system to refuse to comply. David Greene, a lawyer for the digital rights group Electronic Frontier Foundation, told Reuters that part of him found the list “horrendous,” even though he could see the case for fighting inflammatory suggestions.