Start with the uncomfortable answer: for most people who use it, SmallSEOTools' AI Content Detector is already the right tool and switching would be a waste of money. It is free, needs no account, and handles 2,000 words a check. The question worth asking is not which tool is better, it is whether your situation has outgrown a free one.
Paste some text or load the example to estimate AI likelihood.
Verified on smallseotools.com/ai-content-detector, checked 16 August 2026. Yes, it still offers AI detection; free tool sites rotate their line-ups, and this one has not dropped it.
| Detail | What the page states |
|---|---|
| Cost | "No charges are associated with using our AI tester" |
| Registration | "this AI detector won't ask you to go through the hassle of getting registered" |
| Length per check | "Up to 2000 Words will be used" |
| Number of checks | "There is no restriction on the number of times you can use this AI content detector" |
| Advertised accuracy | "Accuracy 99.9%" |
| Languages | "including French, German, Portuguese, Spanish, Italian, and more" |
| Upload formats | .txt, .doc, .docx, .odt, .pdf, .rtf, .tex |
Two observations from the page itself rather than its copy. It loads Google's publisher ad tag, which is how a site giving away 2,000 word checks with no signup pays for the compute. And it loads reCAPTCHA, so heavy repeat use will meet a challenge at some point.
One more, and it is the most useful fact on this page. SmallSEOTools does sell paid plans, at pro.smallseotools.com/pricing: a plagiarism checker at $9.99 a month for 40,000 words, a paraphraser at $9.99 a month, image to text at $4.99, a DA checker at $5.99, and others. The AI Content Detector is not among them. There is no upgrade path. What you see is the whole product, permanently, which means nobody is trying to convert you and the free tier is not a trap. It also means the tool will never grow features for you.
The page states "Accuracy 99.9%" and that "The results of our AI checker are fully accurate." That is the vendor's published claim about its own tool. No test set, no methodology and no evaluation date are published alongside it, and no independent benchmark exists on which these detectors have been measured against each other.
This is close to standard in the category. The safer reading, for any detector including ours, is that no bare accuracy percentage means anything without a published method behind it.
If you fit any of these, do not spend money. There is nothing in a paid tool that improves your situation.
You check occasionally and privately. A few paragraphs, once or twice a week, nobody else sees the result. Free wins outright, and paying would buy you features you would never open.
You do not want an account. No email, no password, no marketing list, nothing stored under your name. Every paid alternative on this page requires a login before it does anything useful. That is a real cost and it is fair to refuse it.
Your text is not English. The page lists French, German, Portuguese, Spanish, Italian and others. That matters, because several paid detectors, ours included, are English-only. On non-English text a free multilingual tool beats a paid monolingual one at any price.
You already live in the toolbox. SmallSEOTools carries a large collection of free utilities, and the detector sits alongside the word counter, the plagiarism checker and the rest. If those are already your bookmarks, adding a separate vendor for one job creates friction with no payoff.
Your checks are one-offs you will never need again. No history means nothing to manage, which is a feature when there is nothing worth keeping.
Not criticism, just the shape of the thing. A tool that costs nothing and stores nothing about you also cannot do the following.
It cannot give you a record. Nothing links the check you ran in March to the client conversation in June. When you are asked "did you check this, and when", you have a memory and a screenshot.
It cannot give you evidence anyone else will accept. A screenshot of a percentage is not a document. If a client, an editor or a committee is going to review the result, they will want something dated, structured and exportable.
It cannot handle volume. 2,000 words a check, one paste at a time, with a captcha waiting for enthusiastic users. Forty articles is forty pastes.
It cannot be automated. There is no API for the AI detector, so it cannot sit inside your publishing workflow or your submission pipeline.
It cannot tell you which sentences did it. A single document score sends you back to read the whole thing yourself.
If none of those gaps hurt, you have your answer already and you can stop reading.
PrePostSEO's AI Content Detector is the closest like for like: another free detector inside a large tool collection, no charge, upload of .doc, .docx, .txt and .pdf. Its visible copy does not state a word limit; the page's own script sets a MAX_WORD_LIMIT of 2000 (prepostseo.com/ai-content-detector, checked 16 August 2026). If you want a second opinion from a different free engine, this is it. Running both is a reasonable habit, because disagreement between two detectors tells you more than agreement from one.
ContentDetector.ai used to belong on this list and no longer does. On 16 August 2026 the domain returned an HTTP 301 to moxby.com/marketplace/ai-content-detector, where the detector is a marketplace mod inside a browser workspace product and the listing states the "Pro plan" is required.
AI Detector Pro is paid, and it bundles detection with rewriting. Free tier is 3 AI scans a month; Basic was listed at "$27.98 $13.99 with 50% off" monthly (aidetector.pro/pricing, checked 16 August 2026).
TraceGPT, from PlagiarismCheck.org, is for institutions: LMS integrations, plagiarism and AI scanning combined, prices starting "at $2.08/month" with organisational plans quoted rather than published (plagiarismcheck.org, checked 16 August 2026). Not the right shape for an individual.
Honestly: only above a certain volume and only when someone else is going to read the result.
The box at the top runs with no account, giving 3 checks a day pooled across the AI Detector and the Document Detector, capped at 1,000 words. That is a lower free ceiling than SmallSEOTools offers, and we are not going to pretend otherwise. A free account raises it to 60 checks a day at 5,000 words. Starter gives 200 a day, Pro and above unlimited. Minimum 25 words. Scores band as under 30 "likely human-written", 30 to 69 "mixed signals", 70 and above "likely AI-generated".
Paid plans, published: Starter $9.99 a month or $7.49 billed annually, Pro $19.99 or $14.99, Business $39.99 or $29.99, Enterprise $79.99 or $59.99, with annual 25 percent cheaper. Starter adds sentence-level analysis and PDF export. Pro adds a Chrome extension and a REST API. Business adds teams and branded reports. File upload, URL scan and bulk scan are available.
The limitation that should stop some readers here: TextSight's detector is English-only, a DeBERTa, RoBERTa and ELECTRA ensemble with a known false-positive bias against writers who learned English as a second language. If you check French or Spanish text, or you check English written by non-native speakers and a wrong answer has consequences, the free multilingual tool you are already using is the safer choice, not the worse one.
Three questions, in order.
Does anyone other than you read the result? If no, stay free. Do you check more than a few thousand words a week? If no, stay free. Do you need the check to happen automatically or in bulk? If no, stay free.
If all three are no, close this page and go back to the tool you were using. That is the honest recommendation, and it costs us the sale.
The deeper head-to-head: feature table, where GPTZero wins, where TextSight wins, and migration steps.
Read the comparePerplexity, burstiness, and transformer scoring explained, so you can read any detector's verdict critically.
Read the guideWhy detectors over-flag ESL and formal writing, and how sentence-level evidence helps you defend real work.
Read the guideThe full ranking with detection approach, pricing, and use-case fit side by side.
See the rankingStart with TextSight's free tier. No card, no signup, no commitment. Your first scan in about six seconds, with the evidence shown line by line.
Honest comparisons vs other tools.