The citation checker that verifies your sources are real, not just formatted

Most citation checkers proofread your reference formatting. None of that helps if a source doesn't exist, was retracted, or never said what you claim it says. Acurio checks those three things: the ones your examiner actually cares about.

Free quick-check, no accountCrossref, OpenAlex, DOAJEU hosting, GDPR-compliant

First: what do you actually need?

My APA/MLA formatting needs fixing
That's a formatting checker's job. Scribbr and QuillBot are built for that. Acurio doesn't proofread citation style.
I need a plagiarism check
That's text-overlap detection. Turnitin and similar tools do that. Acurio asks a different question.
I need to know my sources are real, current, and actually support what I wrote
You're in the right place. That's the whole product.

What a citation checker should check

A citation can be perfectly formatted and still sink your thesis. Three failure modes matter, and formatting isn't one of them.

Does the source exist?

AI writing tools invent references that look real. In a 2025 peer-reviewed study, one in five references GPT-4o generated didn't exist at all. Acurio checks every reference against Crossref, OpenAlex, and DOAJ. Fabricated entries surface immediately.

Was it retracted?

A real paper can still be withdrawn science. Citing a retracted study, knowingly or not, undermines the argument built on it. Acurio flags retracted and corrected sources in the same pass.

Does it support your claim?

The hardest failure to catch: a real source cited for something it never says. Acurio reads your uploaded source PDFs and compares every claim in your text against the actual passage. Supported, partial, or unsupported, with the exact quote.

Tool comparison

Citation tools do different jobs

None of these tools is a substitute for the others; they answer different questions. Here's who checks what, based on each vendor's own documentation.

Acurio Scribbr QuillBot Turnitin
Source exists (not AI-invented) Yes: Crossref, OpenAlex, DOAJ No. Built for formatting checks. No. Built to generate citations. Not its focus
Retraction status Yes No No No
Source supports the claim Yes: reads your uploaded sources No No No
Citation formatting (APA, MLA, …) Not its focus Yes: APA 6th/7th checker Yes: 1,000+ styles No
Plagiarism / text overlap No Separate tool Separate tool Yes: Similarity Report
AI-writing detection No Separate tool Separate tool Yes

Competitor capabilities as of July 2026, from each vendor's public documentation (linked in the column headers); features change, so verify current capabilities. All trademarks belong to their respective owners.

The existence and retraction checks are free to try. Paste your reference list:

Run the free quick-check
Demo

Free bibliography check.

Paste your bibliography. Acurio instantly checks every entry against Crossref & OpenAlex and flags retracted papers. Try it right here.

Paste your bibliography. Acurio instantly checks every entry against Crossref & OpenAlex and flags retracted papers.

Claim support: the check no formatting tool can do

A citation is a promise: “this source backs this sentence.” The only way to verify the promise is to open the source and read it, which is exactly what Acurio does. It extracts every claim in your text, finds the relevant passage in the source you uploaded, and shows both side by side.

Claim in the thesis

“Children with targeted support consistently achieve significantly higher completion rates (Weber 2021, p. 213).”

What Weber 2021 actually says, p. 213

“In two of the four cohorts there was a positive but not consistently significant association.”

Acurio verdict

Partially supported. The source backs a weaker claim than the text asserts: overstatement.

Formatting checkers see a flawless citation here. The reference is real, the style is correct, and the claim is still wrong.

Retraction check

Has this paper been retracted?

Thousands of papers are retracted every year, for fraud, fatal errors, or fabricated data, and they keep getting cited for years afterwards by authors who never checked. Retraction status isn't printed on the PDF you downloaded three years ago. Acurio checks every reference for retractions and corrections automatically, in the same pass as the existence check.

The free quick-check includes retraction status. Paste any reference list, no account needed.

Turnitin checks plagiarism, not sources

Good: keep using it. Turnitin's Similarity Report finds text overlap, and its AI-writing detection estimates whether text was machine-generated. Both are about the text itself. Neither opens your sources.

A hallucinated citation passes a plagiarism check clean. A fabricated reference is original text; there's nothing to match against. Similarity: 0%.

A misquoted real source passes too. Paraphrasing a source into something it never said is exactly what plagiarism tools are designed to accept as your own words.

Different question, complementary answer. Turnitin asks: is this text original? Acurio asks: are the sources behind it real, current, and correctly used? Serious work needs both answers.

Acurio doesn't replace your plagiarism check. It closes the gap that one leaves open.

Built for people whose name is on the work

Students Check your thesis before submission, especially if AI helped anywhere in your workflow. Your name is on the bibliography, not the model's.

Researchers Verify a manuscript's reference list before the reviewers do. Retractions and overstated citations surface before submission, not after.

Supervisors & examiners Check citation fidelity across whole submission batches, with a verdict and source passage per claim. Defensible in front of any board.

Frequently asked questions

What does a citation checker actually check?
Most check only formatting: APA or MLA punctuation and matching in-text citations to the reference list. Acurio checks whether each source exists, isn't retracted, and genuinely supports the claim it's attached to.
Is there a free citation checker?
Yes. Acurio's quick-check lets you paste your reference list and checks existence and retraction against Crossref, OpenAlex, and DOAJ, no account needed. Full claim-by-claim checking of a thesis requires an upload and a plan.
How do I check if my citations are real?
Search each DOI on Crossref and open the source to confirm it says what you cited. Or paste your whole reference list into Acurio's quick-check and verify all of them at once.
Can a citation checker tell if a source supports my claim?
Formatting tools can't; they never open the source. Acurio compares each claim in your text against the actual text of the sources you upload and flags where the source doesn't back you up.
How do I know if a paper has been retracted?
Retractions are recorded in the scholarly databases, not on your downloaded PDF. Acurio checks retraction status for every reference automatically; it's included in the free quick-check.
Does Acurio replace my plagiarism check?
No. Plagiarism tools check text overlap; Acurio checks whether your sources are real and support your claims. Different problems, and serious work needs both.

Your bibliography, verified.

Existence and retraction free in seconds. Claim-by-claim verification for the whole thesis when you need it.