Claude, ChatGPT, Grok and Muse: four assistants making four different bets

Four assistants, four different bets about what this technology is for. Claude is betting on doing long careful work. ChatGPT is betting on being the one app that does everything. Grok is betting on speed and on living inside a social network. Muse, which is Meta's and the newest of the four, is betting that you would rather delegate a task than have a conversation.

Most comparisons of these four are a benchmark table and a winner. This is not that, because the benchmark winner changes every six weeks and it has almost never been the reason anyone switched. What follows is what each one actually is, what it costs, and the question that decides it for you.

What each one is, in one paragraph

Claude, from Anthropic. The one people keep for long documents and for code that spans many files. Its newest model, Opus 5.5, arrived on 22 September 2026, and Anthropic says it matches the older and more expensive Fable 5.1 on most work while costing 40 percent less to run. The free plan is unusually complete: web search, file handling, running code, and Artifacts, which are small working apps it builds beside the chat.

ChatGPT, from OpenAI. The broadest surface of the four. Images, voice, documents, custom assistants and a large app ecosystem in one place. If you want one subscription that does the most different things, this is still the one, and its free tier is generous enough that a lot of people never pay.

Grok, now from SpaceXAI. Built around speed and around real-time access to what is being posted on X, which is a genuine difference rather than a marketing line: it is the one that knows what happened an hour ago. It comes free with rate limits, in paid SuperGrok tiers, and bundled into X's own subscriptions.

Muse, from Meta. The newest and the odd one out. It is an agent rather than a chat window: you give it a goal, such as sorting an inbox or booking something, and it works through the steps. Meta's own page lists email, reservations, shopping, calendars and fitness plans. It carries Meta's terms, which means the account sits alongside the rest of your Meta account.

What they cost

The question that actually decides it

Not which is smartest. Ask instead what you want it to do with its hands.

• Do you want it to write, read and think with you? That is Claude and ChatGPT territory, and the choice between them is taste.
• Do you want it to know what is happening right now? That is Grok, and the others are not close on that one thing.
• Do you want it to go away and do something, with access to your accounts? That is what Muse is for, and it is also the reason to be careful with it.

Those are genuinely different products wearing similar interfaces. A benchmark that ranks them on the same test is measuring the part where they overlap, which is the part you will spend the least time in.

How they differ on the jobs people actually do

Long documents. Claude is still the one people describe as reading rather than skimming, and it holds an argument across many pages. ChatGPT is close. For a contract or a paper, this is where a week of testing will tell you more than any review.

Code. This moves with every release, which is exactly why it is the worst thing to sign an annual plan over. Claude's recent work has gone into long multi-file jobs, and Anthropic's own examples are about migrations finished in a day. ChatGPT remains strong and has the wider set of surrounding tools.

Current events. Grok wins and it is not close. Real-time access to X is the product, and the others are working from search results.

Getting something done without you. Muse is the only one of the four built around this from the start. Whether that is what you want depends entirely on how you feel about the next section.

The part nobody puts in a comparison table

An assistant that acts on your behalf needs permission to act on your behalf. Muse sorting your inbox means Muse reading your inbox. That is not a criticism, it is the deal, and Meta's terms are clear about the consequences: Meta may monitor, log, review, suspend, block or modify what the agent does, and may suspend or terminate access to Muse and to associated Meta accounts.

For a lot of people the associated Meta account is Facebook, Instagram and WhatsApp together. That is worth knowing before you connect anything, and it is the single biggest practical difference between Muse and the other three, none of which can take your social accounts with them.

So which one

1. If you write for a living, or read for a living: Claude, with ChatGPT as the free second opinion.
2. If you want one subscription to cover the most ground: ChatGPT.
3. If your work depends on knowing what was said today: Grok, and pay for the tier that matches how much you actually use it rather than the one at the top of the page.
4. If you want to delegate tasks and you are comfortable with Meta holding the keys: Muse, and read the terms first.
5. If you are not sure: none of them, yet. Every one of the four has a free tier, and a fortnight of using the free ones on real work will answer this better than any article.

A warning about every comparison, this one included

Whichever model was released most recently looks best, because the writer tested it last and wrote while impressed. Opus 5.5 is a week old as this is published, which should make you slightly more suspicious of the nice things said about it here, not less.

The test that has never failed: take the three tasks you actually give an assistant most often, the boring repeated ones rather than the impressive ones, run them on two of these for a week, and count how often you had to fix the answer. That number is worth more than every benchmark on the internet.

Offers on these tools, checked by hand

Sources

Claude's plan and model prices and the Opus 5.5 claims are from Anthropic's own pricing page and announcement, read on 24 September 2026. ChatGPT's price and student offer are from OpenAI's own pages. Muse's description and terms are from muse.ai and its terms page, read on 29 September 2026. Grok's pricing is attributed above and could not be opened from our servers. Prices on all four move, so check before you plan a budget around any of them.