It depends on how much of an absolutist you want to be. No government allows absolute freedom of speech. Libel, slander, and incitement of violence are all forms of speech that are illegal in basically every country. If your platform refuses to remove these forms of speech, you would be protecting what is generally not considered to be free speech, and it’s possible you could even be held legally liable for allowing that kind of speech to spread on your platform.

If you decide not to be a free speech absolutist, and instead define free speech as legal speech, then things get complicated. In the U.S., the Supreme Court has held multiple times that hate speech is protected under the First Amendment, so censoring hate speech would mean your platform wasn’t allowing all forms of, “free speech.” However, the U.S. has much broader protections on speech than most Western countries, and hate speech is illegal in much of Europe.

So, TL:DR; free speech is a sliding scale, and many countries wouldn’t consider hate speech to be protected form of speech. By those standards, you could have a platform that censors hate speech but still maintains what is considered free speech. However, by other countries’ standards, you would be censoring legal speech.