ChatGPT and Gemini are both general assistants that write. The practical difference is where each one sits. Gemini is part of Google's apps, so it suits writing that happens in Gmail and Google Docs. ChatGPT is its own app that you bring your writing to, and in our tests it wrote short, usable messages and strong stories.
We can only speak about quality for one of them. We have tested ChatGPT's model in our own blind writing tests. We have not tested Gemini, so this page has no Gemini scores and does not name a winner. It sorts the two by job and shows you how to settle it on your own writing.
The short version
| Tool | What it is | Good for | Watch out for |
|---|---|---|---|
| ChatGPT | OpenAI's general assistant | Short messages you can paste as they are, and long stories | Scored low on sounding like a person in our tests |
| Gemini | Google's general assistant | Writing inside Gmail and Google Docs | We have not tested it. Gemini inside Gmail and Docs is listed under Google's paid plans |
| Hemmingway | Our writing app, on our own model | Emails and messages that have to sound like you | Not a general assistant. Not for long fiction. English-first |
What each is built around
ChatGPT. OpenAI's site describes one place to chat, work and code. For writing, it says ChatGPT turns rough notes into clear writing and drafts messages, notes, plans, stories and posts. It sits next to image creation, voice and code, and the site says it can connect to work apps such as Gmail and Slack. A free version is open to everyone, with limits.
Gemini. Google's site describes Gemini as a personal assistant, with a free plan for anyone with a Google Account. The part that matters for writing is Gemini inside Google's own apps. In Gmail, Google says it can write an email from a prompt, turn rough notes into an email that is ready to send, suggest replies that fit the thread, sum up a long conversation and pull in details from your Drive files. Google lists Gemini in Gmail and Docs under its paid plans.
Put simply, ChatGPT is a place you go to write. Gemini is a helper inside the place you already write, if that place is Google's.
What our tests found about ChatGPT
The ChatGPT model in our tests is GPT-6 Astra. Three of the four tests are our own benchmarks: blind, run in both orders, with a judge that is not one of the models being judged.
- Everyday messages. On eighty real email and message requests it scored 976 on CommunicationBench. Its messages were short, about 59 words on average, and it almost never wrapped them in commentary. What you get can be used as it is.
- Sounding like a person. Asked which of two replies a person wrote, the judge did not often pick GPT-6 Astra's. It scored 964 on Human-Likeness, below Claude's models, GLM-5.3, Kimi K3 and Hemmingway-1.
- Stories. It scored 1312 on StoryBench, the second-best story writer on our board. Only Claude's Fable 5.1 was ahead.
- Reading people. On the public EQ-Bench 4, GPT-5.5 scored 1316, fourth in the comparison.
None of this tells you anything about Gemini. It was not in the tests, and a missing score is not a bad score.
Which to use, by job
- Replying to mail in Gmail. Gemini, because it is in the window where you are already writing. There is nothing to copy across.
- An email you write somewhere else. ChatGPT. In our tests its messages were short and came with almost no commentary to cut.
- A story. ChatGPT is the one we can vouch for. If long fiction is your main job, Claude did better still in our tests: Claude vs ChatGPT for writing.
- A long document in Google Docs that draws on your own files. Gemini, for the same reason as Gmail.
- Tidying rough notes into a clean paragraph. Both say they do this. Try your own notes in each.
- A message that must sound like you, to someone who knows you. Neither is built around that. This is where a writing tool fits.
Where Hemmingway fits, and where it does not
Hemmingway is our own writing app, and its model, Hemmingway-1, is a 27B model trained for the writing people send to each other. In the same tests it scored 1026 on everyday messages and 1032 on Human-Likeness, above GPT-6 Astra on both. You tell it who people are, and it writes to each of them the way you would. In the apps for Mac, Windows and Android it drafts replies to your mail and chats for you to send. Hemmingway vs ChatGPT and Hemmingway vs Gemini go further.
It does not replace either assistant. It is not for code, research or questions. Large models, GPT-6 Astra among them, write better long stories. It is English-first, and it can be wrong and still sound certain, so do not use it for medical, legal or money decisions.
A test you can run this afternoon
With no Gemini scores from us, the honest answer is to run your own test. Use three pieces of writing, not one, because the two tools may not win the same ones.
- A hard email. Pick one you have been putting off. Give both tools the same facts in the same words, and ask for the email only, one version.
- A short story. Ask each for about 300 words on the same idea, with the same character and the same ending.
- A rewrite. Paste in a paragraph of your own and ask each to make it clearer without adding anything.
Then check four things for each result.
- Would you send or use it with no edits?
- Did it add a fact you did not give it, such as a date or a reason?
- Did it keep to the length you asked for?
- Read it aloud. Does it sound like you, or like an assistant?
Run each request twice. One good answer can be luck. The tool you would trust is the one that gives you something usable both times.
Try HemmingwayDownload the app
Common questions
Is ChatGPT or Gemini better for writing?
We can only answer for ChatGPT, because Gemini was not in our tests. ChatGPT's GPT-6 Astra wrote short, usable messages and was the second-best story writer on our board. Gemini's advantage is that it works inside Gmail and Google Docs. Try both on your own writing before you decide.
Is Gemini good for writing emails?
Google says Gemini in Gmail can write an email from a prompt, polish a rough draft, suggest replies and sum up long threads. We have not tested how well it does this. If you already write your mail in Gmail, it is the easiest one to try.
Which is better for creative writing, ChatGPT or Gemini?
ChatGPT is the one we have results for: GPT-6 Astra scored 1312 on our StoryBench, behind only Claude's Fable 5.1. We did not test Gemini on stories. For short pieces, see the best AI for creative writing.
Are ChatGPT and Gemini free?
Both list a free version on their own sites. OpenAI says the free version of ChatGPT is open to everyone, and Google lists a free Gemini plan with a Google Account. Both have limits, and both keep some features for paid plans.
Is there an AI that writes emails better than ChatGPT and Gemini?
In our own tests Hemmingway-1 scored above GPT-6 Astra on everyday messages, 1026 to 976, and on sounding like a person, 1032 to 964. Those are our benchmarks, and Gemini was not in them. The scores are on the model card.