AI Bias Checker
Paste a job advert, an AI-generated answer, a policy or a piece of copy, and see where it carries bias, why, and how to fix it.

An AI bias checker reads a piece of text and flags language that treats people differently because of a characteristic like sex, race, age, disability or class. For each flag it names the type of bias, says who it disadvantages, and gives you a rewrite. Run it on anything an AI system produced or will consume: job adverts, model outputs, screening prompts, policies, training data samples, marketing copy. It checks the words in front of it. It cannot see your data, your model or the decisions they drive, so treat a clean pass as a good sign rather than a sign-off.
How to use the AI Bias Checker
Paste the text you want checked
Any text works: a job advert, an AI-generated answer, a system prompt, a policy paragraph, a piece of marketing copy. Up to 6,000 characters at a time.
Tell it what the text is for
Pick the context: hiring, AI output, customer communication or general. The same sentence can be fine in one and discriminatory in another, and the check is stricter where the stakes are higher.
Read the flagged passages
Each flag quotes the exact wording, names the type of bias, rates severity, and explains who it disadvantages and how.
Apply or reject the rewrites
Every flag comes with a suggested neutral rewrite. Use your judgement. The tool cannot see your context, and a confident flag can still be wrong.
Escalate anything structural
If the bias is in how a decision gets made rather than how it is worded, the fix is in the system. That needs an evaluation, not an editor.
What AI bias actually is
AI bias is a systematic, repeatable error that produces worse outcomes for particular groups of people. Systematic is the important word. A model that gets things wrong at random is inaccurate. A model that gets things wrong in the same direction about the same kind of person every time is biased.
Nobody has to intend it, and it almost never comes from a line of code you can point at. It arrives through the data the system learned from, the way somebody framed the problem, the proxy chosen for something that could not be measured directly, and the people who labelled the examples. Every one of those is a normal engineering decision. Together they are the most common source of harm in deployed AI.
This is a commercial problem as much as an ethical one. In the UK, a system that produces materially worse outcomes for people sharing a protected characteristic can amount to discrimination under the Equality Act 2010, whether a human or a model made the call. Automated decision-making that significantly affects people carries its own obligations under UK GDPR on top.
Examples of AI bias, by type
These are patterns rather than accounts of particular incidents. They are the shapes that keep turning up in real systems, and they are what the checker above looks for in text.
- Historical bias. The data faithfully records a world that was already unequal. Train on a decade of promotion decisions and the model learns who got promoted, not who deserved to. It is accurate about the past and wrong about the future you want.
- Representation bias. A group is in the data, but thinly. Speech recognition trained mostly on one set of accents performs worse on others. The failure is invisible in a single accuracy number and completely obvious to the people it fails.
- Measurement bias. What you can measure is not what you care about. Use "years of continuous employment" as a proxy for reliability and you penalise everyone who took time out to raise a child or recover from illness.
- Aggregation bias. One model applied to groups that behave differently, fitted to the largest one. Clinical thresholds calibrated on one population and applied unchanged to another are the textbook case.
- Label bias. Your ground truth came from people, and people disagree. Toxicity labels carry the labellers' norms, so dialect and reclaimed language get scored as offensive.
- Deployment bias. The system works exactly as designed and gets used for something else. A tool built to rank candidates for review becomes a tool that rejects them, because nobody has time to read past the top ten.
- Linguistic bias. The text itself carries it: gendered job titles, culture-fit language that filters on class, ability-assuming verbs like "walk the floor", age markers like "digital native" and "recent graduate". This is the category the checker catches directly, because it lives in the words.
How to detect bias in AI output
Text screening is the cheapest layer and the only one you can run in a browser. It catches linguistic bias, which is both the most common form in generated content and the easiest to fix, because fixing it means changing words.
It will not catch the rest. Detecting historical, representation or measurement bias needs access to the system: performance metrics broken out by group rather than one accuracy figure, counterfactual tests that change one attribute and hold everything else still, and an honest look at what the training data actually contains.
A proper evaluation runs all of those together and repeats them after every material change to the model, the prompt or the population it serves. Bias is a property that drifts, so testing for it once tells you about one afternoon.
- Screen the text. Run outputs, prompts and templates through a checker like this one before they ship.
- Break out the metrics. Report accuracy, false positives and false negatives per group. Never as a single number.
- Run counterfactuals. Change a name, a pronoun, a postcode or a university, hold everything else constant, see whether the decision moves.
- Audit the proxies. For every input feature, ask what it stands in for and who that disadvantages.
- Keep a human in the loop where the decision matters, and make sure that human can actually overrule it.
- Re-test on a schedule rather than on a hunch, and keep the results as evidence.
Where UK rules bite
The UK has no single AI act. The obligations come from instruments that already applied to you, now read across to automated systems.
The Equality Act 2010 prohibits direct and indirect discrimination across nine protected characteristics. Indirect discrimination is the one that catches most AI systems: a neutral-looking rule that puts a group at a particular disadvantage is unlawful unless it is a proportionate means of achieving a legitimate aim. A model is a rule.
UK GDPR and the Data Protection Act 2018 add duties around fairness, transparency and solely automated decisions that produce legal or similarly significant effects on people. The ICO publishes specific guidance on AI and data protection, including on bias and discrimination.
Sector regulators stack their own expectations on top. Financial services, healthcare and employment each have more to say. None of it is satisfied by running a text checker, which is why this page ends with an offer to look at the system rather than the sentences.
What this tool cannot tell you
It reads text. It has no access to your model, your training data, your evaluation metrics or your decisions. It can tell you whether a passage of writing carries bias a reader would recognise. It cannot tell you whether a system is fair.
It is also a language model itself, so it has the same failure modes it is looking for. It will over-flag cautious writing, miss bias that depends on context it cannot see, and carry the norms of whatever it was trained on. Treat every flag as a prompt for a human judgement.
Run the checker and nothing you paste is stored. The text goes to the model, the result comes back, neither is written to a database. Submit the form to unlock more runs or to download the report and the text comes to us with your address, which is what the tick box on that form says. Either way, keep personal data, client-confidential material and anything under NDA out of it. There is no good reason to send any of that to a third-party model to check wording.
Frequently asked questions
The ones that recur most: historical bias (the data records past inequality), representation bias (a group is under-represented), measurement bias (the proxy is not the thing you care about), aggregation bias (one model across groups that behave differently), label bias (human labellers encoded their own norms), deployment bias (the system gets used for something it was not built for) and linguistic bias (the language itself is loaded). A text checker catches the last one directly. The rest need access to the system.
Yes. The first three checks need nothing at all, no account and no email. After that you can unlock seven more by giving us an email address and telling us what you are working on. There is no paid tier.
No. The text goes to the model to produce the result and is not written to any database of ours. We count how many runs happen, never what was in them. Even so, keep personal data and anything confidential out of it.
No, and be wary of anything that claims otherwise. This checks language. Compliance under the Equality Act 2010 or UK GDPR turns on outcomes, the data behind them and the decisions they drive. A clean text screen is a good sign and not evidence.
Because it does not know your context, and because it is tuned to surface things worth a second look rather than to be right every time. It also runs stricter where the stakes are higher, so a phrase that passes in general marketing may get flagged in a hiring context. Over-flagging is the intended failure mode. Dismiss what does not apply.
Yes, that is one of the two things it does best, alongside job adverts. Paste the generated output before it ships. It earns its keep most on anything a model produces at volume, where nobody is reading every item.
If it is in the wording, apply the rewrite and fix the template or prompt that produced it, so the next hundred outputs come out clean too. If the same kind of flag keeps appearing, the problem is upstream in the prompt, the model or the data, and it needs evaluating properly.
Bias in a demo is embarrassing. Bias in production is a liability.
If an AI system you are building or buying makes decisions about people, someone will eventually find the bias in it. Better that it is you. We run independent technical assessments of AI systems, including the evaluation and governance work UK regulators increasingly expect to see.
Talk to us about an AI assessmentRelated from Metamindz
- Technical due diligence and AI system assessmentIndependent evaluation of an AI system: what it does, where it fails, and what it exposes you to.
- AI adoption for engineering teamsGetting a team using AI properly, including the evaluation and review habits that keep bias out of production.
- Fractional CTOSenior technical leadership on a retainer, for when these decisions need an owner.
- All free tools
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