The ranking criterion, stated up front: not output quality, not speed. A thesis tool is good in Canada if, after you use it, you can still show your supervisory committee which words, analyses and ideas are yours. Every Canadian graduate school that has published guidance requires exactly that, so any tool that makes the boundary harder to see is a bad tool no matter how well it writes.
| # | Tool | Best for | Defensibility under a committee | Price we could verify |
|---|---|---|---|---|
| 1 | Tesify | Writing the whole thesis: chapter scaffolding, structure, references | High — the structure is generated, the arguments stay yours and stay attributable | Free entry tier; paid pricing shown at signup |
| 2 | ChatGPT | Thinking out loud, unsticking a paragraph, explaining a method | Medium — depends entirely on your own record-keeping; invents citations | Not verifiable — the pricing page blocked our request |
| 3 | Grammarly | Sentence-level language and tone after the argument exists | Medium — safe when used for surface language, less so with full-sentence rewrites | Free tier; one paid individual tier (currency varies by region) |
| 4 | Scribbr | Human proofreading of a finished draft | Depends on your institution’s editing rules, which usually require prior approval | Not verifiable — the site blocked our request |
| 5 | QuillBot | Paraphrasing individual passages | Low for thesis work — the paraphrase becomes untraceable to you or the source | Free tier; premium billed annually (currency varies by region) |
| — | “Humanizer” / “undetectable AI” tools | Nothing you should be doing in a thesis | None — the product’s purpose is to defeat the audit trail | n/a |
Two honesty notes before the detail. First, prices are shown in whatever currency your billing region resolves to: the figures we read were served in euros, so a Canadian dollar amount has to be checked at your own checkout rather than taken from any article, including this one. Second, several vendors publish no static price we could read at all — those are marked “not verifiable” above rather than guessed. A comparison that invents numbers is worse than one that admits a gap.
1. Tesify — best for the thesis as a whole
Most AI tools are sentence-scale. A thesis is a 40,000-to-80,000-word argument with a chapter architecture, a reference apparatus and an examiner at the end of it, and sentence-scale tools do not help with any of those three things.
What a thesis-shaped tool does is hold the structure steady while you fill it: chapter scaffolding that matches how graduate work is actually examined, referencing that stays consistent across a document too long to keep in your head, and a working surface where the argument you write remains identifiably yours. Over 9,000 students and 15,000+ chapters have been built this way, and the writing stays 100% written by you — which is precisely the property your committee is checking.
The free tier is the sensible entry point: it is enough to see whether the structure fits your programme’s thesis format before you commit anything.
Start a thesis in Tesify and keep the scaffolding while every argument remains yours.
2. ChatGPT — best general reasoning partner, worst citation behaviour
A general chatbot is genuinely good at the things graduate students are bad at alone: explaining an unfamiliar method in plain language, arguing against your own position so you can find the weakness, and turning a tangled paragraph into three clear ones.
Two failure modes matter for a thesis.
- Fabricated references. Plausible-looking citations to papers that do not exist are the single most common way graduate students get caught out. Every reference a general model produces has to be resolved against the actual record before it enters your document. If you cannot open it, it does not go in.
- No record of what it touched. Chat history is not a work record. If you cannot reconstruct which paragraphs were shaped by a model, you cannot write an accurate disclosure statement, and you cannot answer a committee member who asks about page 74.
We could not verify ChatGPT’s current consumer pricing: both the OpenAI and ChatGPT pricing pages returned a block to our requests. Rather than repeat a number from a secondary source, we are leaving it unstated. Check it yourself before subscribing.
3. Grammarly — good at language, and worth reading its own menu
Grammarly is a competent surface-language tool. Its own plans page describes a free tier that fixes spelling and grammar, shows writing tone and includes a capped number of AI prompts, and a single paid individual tier that adds full-sentence rewriting, tone adjustment and unlimited personalised suggestions. Its plans page also states the company is “trusted by over 40 million people and 50,000 organizations.” The paid figure was served to us in euros; treat the currency as region-dependent.
The more useful thing to notice is what else is on the menu. Grammarly’s own tools list includes a Grammar Checker, a Plagiarism Checker, an AI Detector, an AI Humanizer, a Paraphrasing Tool, a Citation Generator and an AI Grader.
That is one vendor selling the detection of AI text and the concealment of AI text in the same product family. Nothing about that is illegal, and the individual features have legitimate uses. But a graduate student should read it as a signal about the category rather than as a menu of things to use — and should notice that “humanize” is a euphemism for “make the origin harder to establish”, which is the opposite of what your committee requires.
4. Scribbr — a human service, governed by your editing rules
Scribbr sells human proofreading and editing rather than generation, which puts it in a different regulatory category: your institution’s rules on external editors, not its rules on AI. Those rules are real and often stricter than students expect. The University of Toronto’s School of Graduate Studies permits an external copy editor only with prior approval and a strong rationale, requires that the intellectual content of the thesis cannot be modified through the external editing process, and requires the student to identify the editor’s contribution in the thesis document.
So the question is not “is Scribbr good”, it is “has my supervisor approved external editing, and how will I disclose it”. We could not verify Scribbr’s current per-word pricing: the site blocked our request. Get a quote directly and get the approval first.
5. QuillBot — the tool whose free tier tells you the problem
QuillBot’s premium page lists what its plans include, and the list is worth quoting because students rarely read it before signing up. The free plan advertises paraphrasing up to 125 words in two modes, basic grammar fixes, basic summaries, limited access to an AI Detector — and “Humanize up to 125 words, 6 uses/day”. The premium plan, billed annually, advertises full access to paraphrasing, full access to humanizing, full access to the AI Detector, and “Prevent accidental plagiarism”. Its footer tool list includes an AI Humanizer, an AI Detector, a Plagiarism Checker and APA, MLA and Chicago citation generators.
Used narrowly — rephrasing one sentence you have already understood and will cite — a paraphraser is unremarkable. Used the way it is marketed, it produces text whose relationship to its source and to you is unrecoverable. That is patchwriting with better grammar, and it is the failure mode that actually ends up in misconduct proceedings. It is also invisible to a similarity percentage, which is one of several reasons the similarity score is not the safety check students think it is.
The recommendation, and the runner-up for a tighter budget
Recommendation: Tesify, because it is the only category on this list built around the object you are actually producing — a structured, referenced, examinable document — rather than around sentences.
Runner-up on a tighter budget: Grammarly’s free tier plus Zotero. Both cost nothing, they cover the two jobs a student most often pays for separately (surface language and reference management), and neither introduces a feature that would embarrass you at a defence. Before you pay for a reference manager at all, check what your university library already licenses — our comparison of Zotero, Mendeley and EndNote for a Canadian thesis sets out what is typically already covered by your tuition.
How to use any of these without breaking your programme’s rules
- Get approval before you start, not before you submit. Canadian guidance is written around prior approval by the supervisor and supervisory committee — the detail is in our guide to what AI use Canadian universities actually permit.
- Keep a tool log. One line per session: tool, chapter, task. It takes seconds and it is the only thing that makes an accurate disclosure statement possible six months later.
- Resolve every citation. If a tool produced a reference, open the source before it enters your bibliography.
- Never use a humanizer on thesis text. There is no version of that decision that improves your position at a defence.
- Keep your drafts. Version history is the cheapest evidence you will ever produce that the work is yours.
What about analysis and data tools?
They sit outside this list because they answer a different question, but they carry the same reproducibility logic — what you can show, not what you remember. If you are still choosing, our comparison of SPSS, R, jamovi and Stata for a Canadian thesis covers licensing and what your institution may already provide.
Frequently asked questions
What is the best AI tool for writing a thesis in 2026?
For a Canadian thesis, the one that leaves your contribution visible and defensible. Thesis-shaped tools built around chapter structure and referencing score best on that test; general chatbots are usable with disciplined record-keeping; paraphrasers and humanizers score worst.
Is Tesify better than ChatGPT for a thesis?
They are different categories. ChatGPT is a general reasoning partner with no thesis structure and no reference integrity. Tesify is built around the document — chapter scaffolding and referencing — while you write the arguments.
Does Grammarly really sell an AI humanizer?
Its own tools menu lists an AI Detector and an AI Humanizer alongside a Plagiarism Checker, a Paraphrasing Tool, a Citation Generator and an AI Grader.
Is QuillBot allowed for a thesis?
That is your committee’s decision, not the vendor’s. Understand that its marketed use — paraphrasing and humanizing at scale — produces text you cannot trace, which is exactly what a supervisory committee is trying to be able to trace.
How much does each tool cost in Canadian dollars?
Vendor pages display the currency of your billing region, so the figure you see may differ from the one we read. Check at your own checkout, and be sceptical of any article quoting a precise CAD price without saying when it was checked.
Why could you not verify some prices?
Because the vendors’ pricing pages blocked our requests. Rather than repeat second-hand numbers, we named the gaps. A fetch failure is a fact about our request, not about the product.
Will my university give me any of these for free?
Sometimes. Institutional licences most often cover reference managers, statistical software and productivity suites rather than AI writing tools. Ask your library before you subscribe.
Do these tools trigger a plagiarism flag?
Similarity software measures textual overlap with indexed sources, not tool use. That is a separate question from whether the use was approved, and neither answers the other.
Can I use an AI detector on my own work first?
You can, but the result is not evidence of anything your committee will accept, in either direction. Approval and disclosure are what your programme asks for.
Is a paid tier necessary?
Not to finish a thesis. A free writing surface, a free reference manager and disciplined record-keeping will get a thesis submitted; paid tiers buy convenience.
What single habit matters most?
Keeping a one-line log of every tool session. It costs nothing and it is what makes the disclosure statement and the defence answer both possible.