Revise Blog - Building a post-AI word processor
Gemini vs ChatGPT for writing
Plans, context limits, drafting tools, and document handling, checked against Google’s and OpenAI’s own pages
Artur Sapek, Founder of Revise7 min read
To compare Gemini and ChatGPT for writing, it helps to look at the standalone assistants separately from their office-suite integrations. The practical differences are in plan price, published limits, the drafting workspace each one offers, and how each one works with Google Docs or Word.
I have spent the past year building Revise, a word processor that runs GPT and Gemini models. Plans and limits come from each vendor’s own pages, and the proofreading numbers come from our public benchmark.
Gemini vs ChatGPT at a glance
| Gemini | ChatGPT | |
|---|---|---|
| Free plan | Yes (32K-token context, standard usage limits) | Yes (3 file uploads a day, 27K-token Instant context) |
| Paid from | $4.99/mo (Google AI Plus) | $8/mo (ChatGPT Go) |
| AI models | Gemini | GPT |
| AI capabilities | Canvas docs you edit directly or through prompts, exports to Google Docs | Writing blocks for revising a draft or selection, reads uploaded DOCX and PDF |
| Largest published context | 1M tokens (Google AI Pro and Ultra) | 400K tokens (Pro, reasoning models) |
| Word files | Reads uploads, exports responses to Google Docs, returning an edited .docx not documented | Reads uploads, creates files through ChatGPT Work, edits inside Word through its add-in |
Paste a draft below and ask for an edit to see how a model handles your own writing. It opens in Revise in your browser without an account. The free plan runs GPT-6 Luna, subject to a daily AI limit, and Gemini 3.8 Flash comes with Plus.
Key differences for writers
These are the five areas that matter most for writing work. Each one ends with the product that has the edge based on the evidence we have, or says that neither does.
Drafting quality and style
We have no controlled test of drafting quality, voice, or creativity for either app. Both let you steer their output. ChatGPT has memory, which carries your preferences between conversations, and Gemini has Gems, which are custom assistants available on its free plan. Neither feature shows that one app writes better than the other.
Edge: We don’t have evidence for either, so give both the same brief and compare the results.
Proofreading accuracy
ErrataBench runs models through the same find-and-replace harness on 99,000 words seeded with realistic errors. It calls models through their APIs, not the Gemini or ChatGPT apps. GPT-5.6 Sol with medium reasoning fixed 96.5% of errors, the highest score, and GPT-6 Sol with no reasoning fixed 95.4%. Gemini 3.1 Pro with low reasoning fixed 92.1%, and Gemini 3.7 Flash with medium reasoning fixed 91.4% at about $0.12 per run (full results).
Edge: GPT-5.6 Sol scored highest among the models we tested. That does not make either app the winner, because the model and settings you get vary by plan.
Context and file limits
Google lists 32K tokens of context without a plan, 128K on Google AI Plus, and 1M on AI Pro and Ultra, with up to 10 files per prompt at 100 MB each. OpenAI lists 27K tokens for GPT Instant on Free and 54K on Go and Plus, with 256K for reasoning models on Go and Plus and 400K on Pro. Free ChatGPT accounts can upload 3 files a day.
These are advertised limits. They tell you how much text fits in a conversation, but not how well either model uses it.
Edge: Gemini on Google AI Pro or Ultra, because those plans publish a 1M-token maximum. Google AI Plus lists 128K, which is less than the 256K that ChatGPT Go and Plus list for reasoning models.
Drafting workspace
Both call their document workspace Canvas. Gemini’s Canvas lets you edit the text yourself or ask Gemini, rework a selection, and apply quick edits and formatting. It can turn a draft into slides, an Audio Overview, a quiz, an infographic, or a web page, and share it by public link. ChatGPT’s Canvas opens beside the chat, where you mark up text and get inline suggestions.
Edge: Gemini, if you want to turn one draft into other formats. Both support direct editing and AI suggestions, and we did not run a controlled test of the editing workflow.
Google Docs and Word files
Gemini exports responses to Google Docs and Gmail. Using Gemini inside Google Docs costs more, because for individuals it starts with Google AI Pro at $19.99 a month. In our August 2026 document review test, Gemini in Docs needed some nudging. After that it left comments under the user’s name and made its edits as Google Docs suggestions. Google’s help pages we checked do not describe returning an edited .docx.
ChatGPT reads uploaded .docx files, and ChatGPT Work can create documents, including native Google Docs when the Google Workspace app is connected. Availability depends on your plan. ChatGPT for Word runs as an add-in inside Word and is available on every ChatGPT plan, subject to that plan’s usage limits. In the same test, the ChatGPT app gave detailed feedback but returned a regenerated .docx without tracked changes.
Edge: Gemini is better if you want AI built into Google Docs and have Google AI Pro. ChatGPT is better for Word.
Which should you choose?
Choose Gemini if
- you want the cheapest paid plan (Google AI Plus, $4.99 a month)
- you want AI inside Google Docs and can pay for Google AI Pro
- you want a 1M-token context window (Google AI Pro or Ultra)
- you turn drafts into slides, quizzes, or audio overviews
Choose ChatGPT if
- your documents are Word files
- you want an AI add-in inside Word on your current plan, within its usage limits
- you want memory that carries preferences between conversations
What each costs
Google AI Plus costs $4.99 a month for twice the free usage and 128K context. Google AI Pro costs $19.99 and includes Gemini in Docs, 1M context, and 5 TB of storage. ChatGPT Go costs $8 a month and may include ads, and Plus is $20. OpenAI bills individual plans monthly.
| Tool | Cheapest paid plan | Monthly | Per year | AI on that plan |
|---|---|---|---|---|
| Gemini | Google AI Plus (per month) | $4.99/mo | $59.88 | 2x Free usage and 128K context, Gemini in Docs and 1M context start with AI Pro ($19.99/mo) |
| ChatGPT | ChatGPT Go (monthly billing, may include ads) | $8/mo | $96 | More messages, uploads, and memory than Free |
Running both in one editor
Revise, the browser word processor that publishes this guide, runs GPT and Gemini models (plus Claude and Grok) in one editor and opens and exports .docx files. It shows text and formatting edits as tracked changes. It is a separate editor rather than an add-in for Word or Google Docs, and its Gemini models need a paid plan.
The bottom line
The choice mostly depends on where your documents live and how much you want to spend. Gemini has the cheaper entry-level paid plan and is the better pick for Google Docs if you have AI Pro. ChatGPT is the better pick for Word files.
Sources
Prices and plan details were checked against each vendor’s own pages on October 4, 2026. Prices are in US dollars as each vendor lists them, and some include local tax. Vendors change plans often, so confirm on the linked page before you buy.
- Gemini: Plans, Limits and upgrades, Canvas, Upload files, Export responses, October 2026 model access changes
- ChatGPT: Pricing, Free tier FAQ, File uploads FAQ, Writing blocks, ChatGPT for Word, Capabilities overview, ChatGPT for Word, Creating documents with ChatGPT Work, Google Drive app, Google app data controls, Supported file types, ChatGPT for Google Sheets
