Compare
Copy.ai vs Writefull: what a student writing in Word or Overleaf should pick
Writing a thesis in Overleaf or a paper in Word? Pick Writefull. Its language feedback comes from models trained on published papers, and it checks language directly in LaTeX source. Copy.ai sells AI to marketing, sales and operations teams, and its main pages list nothing for essays, sources or citations.
Writefull also costs one person less than Copy.ai's Chat plan, whether you pay by the month or by the year. Copy.ai's case rests on breadth: a chat workspace for five people running OpenAI, Anthropic and Gemini models, and a long list of free generators.
Prices and features checked on October 17, 2026.
At a glance
Writing assistants help you write; essay generators write the essay for you.
| Product | Type | Paid from | Free tier | Citations | Ghostwriting |
|---|---|---|---|---|---|
| Copy.ai | Essay generator | $29/month | Yes | Not verified | Drafts text when asked |
| Writefull | Writing assistant | US$21/month | Yes | Does not cite | Drafts text when asked |
Feedback trained on published papers
Writefull is a language tool first. Its feedback is tailored to academic writing, and inside Overleaf it can also generate LaTeX tables and equations. LaTeX users value that it understands Overleaf source, and one user's informal grammar test ranked it alongside Grammarly.
The free plan includes the LaTeX tools alongside the language edits, so you can try it on a real Overleaf project before paying anything.
Copy.ai's grammar checker is one free tool among many, beside a paragraph rewriter and a paraphrasing tool, and none of them is pitched at academic writing. Neither product describes feedback on the argument itself, so a supervisor's read still matters.
Citations: neither says it adds them
Writefull doesn't find, manage or format sources. Writefull Cite, sold to institutions only, flags sentences that look like they need a citation but have none, and leaves the citing to you. That's useful in a narrow way: a flagged sentence is a prompt to go and find the paper yourself.
Copy.ai doesn't describe academic sources anywhere on its public pages, and its Workflow credits for “internet research” come without any explanation of citing. With either tool, your reference manager does the real work.
Generating text: an abstract, or anything at all
Writefull mostly edits your own sentences, but its Abstract Generator, Title Generator and Ask AI produce new text when asked. The site now also promotes a separate Papers AI product to “Draft the whole manuscript”, so the brand isn't editing-only any more.
Copy.ai starts at the other end. It writes whatever you ask and takes no position on student work, and its Paragraph Generator suggests using it to “draft literature reviews or discussion sections”, the very parts of a paper a researcher would otherwise write in Overleaf. Hand that in as your own and you're taking an academic-integrity risk.
Where your text goes
Writefull is specific about this. It says it never stores your text or uses it to train its AI, and it asks for consent before sending text to third-party AI services. For a thesis chapter with unpublished results, that's a reason to pick it on its own.
Copy.ai's Chat plan runs on models from OpenAI, Anthropic and Gemini, and the Copy.ai claims covered here don't say how it handles the text you paste in. Read its terms before a draft with unpublished data goes anywhere near it.
Free quotas, prices and billing
Writefull's free plan is a quota of each feature (language edits, paraphraser, title and abstract generators, LaTeX tools), each marked “Limited”, and some users hit the daily quota quickly. Premium is US$21 billed monthly or US$150 a year billed annually, with unlimited edits under fair use. A Group plan is US$285 a year for two seats, billed annually only.
Copy.ai's Chat plan is $29 billed monthly or $288 billed yearly, for five seats. One person pays less with Writefull Premium on either basis. Copy.ai's pricing page lists no free plan; a sign-up prompt on its free tools advertises 2,000 free words a month, with unverified limits.
Both have billing complaints. Some Writefull users report being charged after cancelling and struggling to find the unsubscribe option, and Copy.ai's Trustpilot reviewers describe charges that continued after they cancelled.
Which should you choose?
Choose Copy.ai if your work is marketing or sales writing and you want a shared chat workspace with OpenAI, Anthropic and Gemini models. For academic writing, nothing on its site describes handling a source.
Choose Writefull if you write academic English in Word or Overleaf, LaTeX especially, and want edits from models trained on published papers. Try the free quota, then it's US$21 a month or US$150 a year.
When the trouble is sources and argument rather than sentences, EthiWrite, which we make, is the other route. It cites only from your Library, and Examiner Mode flags unsupported claims and thin evidence without rewriting anything. Citation formatting stops at APA, MLA and Chicago.
FAQ
- Is Writefull free?
- Partly. The free plan gives a limited quota of each feature, and unlimited use needs Premium.
- Which suits a student writing in a second language?
- Writefull, for academic work. Its feedback comes from models trained on published papers and is tailored to academic writing, which is the register you're trying to learn. Copy.ai's tools are pitched at marketing, sales and operations writing.
- Will Copy.ai or Writefull write my essay?
- Copy.ai will write whatever you ask. Writefull's editor works on your sentences, but its Abstract Generator drafts an abstract from your paper and its site promotes Papers AI to “Draft the whole manuscript”. Your school's AI policy applies to both.
- Is Writefull good for maths-heavy LaTeX?
- Opinions split. LaTeX users value that it understands Overleaf source, but other researchers in the same r/academia thread found it correcting mathematics as if it were prose, imposing a serial comma on British English, or twisting their meaning.