Check My Thesis vs. QuillBot

Quick verdict

Choose QuillBot to improve text while you write: paraphrasing, grammar, summarizing, and quick free AI checks.

Choose Check My Thesis to review a finished academic draft before submission: verify every reference against scholarly databases and inspect AI-written passages sentence by sentence.

QuillBot is a drafting companion. Check My Thesis is a pre-submission gate. The overlap is smaller than the "AI detector" label on both makes it look.

The short comparison

What QuillBot does well

QuillBot earns its user base at the drafting stage.

The paraphraser rewrites clunky sentences in several modes, the grammar checker cleans mechanics, and the summarizer condenses sources. For non-native English writers grinding through a thesis, that combination removes real friction.

Its AI detector is free and simple: paste at least 80 words and get a likelihood score from 0 to 100, in several languages. QuillBot also states how it handles uncertainty: when the result is unclear, its model tends to classify texts as human written. (QuillBot AI detector)

The citation generator creates, edits, and saves citations in over 1,000 styles, free and without limits, including citing from an uploaded PDF. (QuillBot citation generator)

Premium, listed at €8.33 per month billed annually as displayed at this update, adds a plagiarism checker and full access to the paid features. (QuillBot Premium)

Where the QuillBot workflow stops

Two gaps matter for submission work.

First, citations. QuillBot's citation tool generates citations. It does not audit the ones you already have. No feature on its pages checks whether a cited source exists in the scholarly record, so a fabricated reference formatted by QuillBot comes out looking perfect and stays fake. Generation and verification are different jobs, and our guide on how to check if a citation is real covers the verification side.

Second, the shape of the AI check. A single likelihood score on pasted text works for a quick look at one passage. A thesis needs something else: which sentences, in which chapters, would draw a reader's attention, across a 120-page PDF.

One more thing said plainly, because students ask: paraphrasing AI-generated text does not convert it into your work. Turnitin states its detection reports text likely generated by AI or modified by an AI paraphraser or bypasser. (Turnitin FAQ) More to the point, your university's rules govern what help is allowed, and undisclosed AI text stays undisclosed AI text no matter how it is rephrased. Use paraphrasing to improve your own writing, not to relabel a machine's.

What Check My Thesis does instead

Check My Thesis reviews the finished draft.

The AI detector scores text sentence by sentence and flags AI-written, mixed, and human passages, with highlights directly on uploaded PDFs. You see the exact paragraphs worth a second look instead of one number for the whole document, which is the difference between fixing three sentences and nervously rewriting a chapter. For how that compares across tools, see our guides to the best AI text detectors for students and top AI detection tools for students.

The citation checker cross-checks every reference against Semantic Scholar, OpenAlex, arXiv, PubMed, CrossRef, Google Books, DBLP, and Open Library, and flags each entry as verified, hallucinated, or outdated. That is the check that catches AI-invented sources, which current models still produce at measured rates around one in five. (JMIR Mental Health, 2025) If that risk is new to you, start with ChatGPT fake citations: what to do.

LaTeX users get the BibTeX cleaner and the citation updater for preprints that later got published.

Check My Thesis does not provide plagiarism or similarity checking. QuillBot Premium includes one, and dedicated options live in our top plagiarism checkers for thesis guide.

Who should use QuillBot?

Use QuillBot while you write.

It fits daily drafting: rewording a paragraph that will not flow, checking grammar in a second language, summarizing a paper before deciding to read it fully, formatting a citation fast. The free tier covers a lot of that, and the price of Premium is low if you write constantly.

Who should use Check My Thesis?

Use Check My Thesis when the draft is done and the stakes arrive.

Before submission you need answers QuillBot does not offer: do all 150 references exist, which metadata is wrong, which preprints went stale, and which passages of the text would read as machine-written to a reviewer. That is one pass through the citation checker and the AI detector, free to start, with full-draft checks as a one-time purchase rather than a subscription.

FAQ

Is QuillBot's AI detector accurate enough for a thesis?

QuillBot offers a free detector with a likelihood score and says unclear results lean toward classifying text as human written. (QuillBot AI detector) Every detector, including ours, produces estimates rather than proof, so for a thesis the useful output is sentence-level location of risky passages you then judge yourself, not any single document score.

Does QuillBot check if my sources are real?

No such feature is advertised. Its citation tool generates and formats citations. Verifying that references exist requires database lookups, which is the job of the Check My Thesis citation checker.

Can I use both?

Comfortably. QuillBot improves the writing while you draft. Check My Thesis verifies references and reviews AI-writing concerns when you finish. They meet at zero points of conflict.

Final recommendation

QuillBot is a good drafting toolkit, and for grammar, paraphrasing your own prose, and quick checks it does its job at a fair price.

For the submission gate, choose Check My Thesis: reference verification against eight scholarly databases plus a sentence-level AI review of the actual PDF you will hand in. Finish the draft with QuillBot if you like, then run the free checks before anyone official reads it.