The commercially useful and honest answer to this question includes the cases where the reader does not need to pay, and this guide, published by iatroX, says so plainly before making any case for a subscription.
The different meanings of "free"
An ongoing free service: available indefinitely without payment, Ask-iatroX among the examples. A restricted tier: free access to part of a product, with the rest paid. A professional-verification requirement: free only to those who can prove a specific status. A trial: free for a period, then paid. And employer-funded access: free to the individual because an institution pays. Each is genuinely free to someone; none is free in the same way, and the differences decide whether a given reader can rely on it.
Genuinely available options
Ask-iatroX: an ongoing free service, clinical answers grounded in UK guidance and SmPC information with linked sources, no verification, no trial period. ChatGPT Study Mode: within ChatGPT's tiers, supporting guided questioning and checking understanding, a genuine free tutoring option for general study. OpenEvidence: advertised free access for verified US healthcare professionals, eligibility stated clearly, which excludes most UK readers from the intended use. iatroX's free question access, including the full PARA bank of more than 1,000 questions, is an ongoing free service rather than a sample.
Other meaningful free offers
Heidi currently advertises free Clinician access for qualifying trainees and students. It is worth discussing for what it is, an ambient documentation and evidence-workflow tool, and not for what it is not, an examination or learning platform. A student who needs documentation support has a genuine free option here; a student who needs question practice or tutoring does not, and this guide does not pretend otherwise.
What justifies paying
Structured practice mapped to a specific examination's blueprint, rather than ad hoc questions. Curriculum fit, content built for the assessment you are sitting. Useful feedback, specific and actionable rather than a score. Integrated tutoring on your own errors. Simulation of the performance the examination actually tests. And learning records that follow you into professional practice. Each of these may be worth paying for even when clinical question-answering is available free, because none of them is question-answering.
iatroX's distinction, made explicit
Readers are not being asked to subscribe to obtain access to Ask-iatroX; it remains free. The paid proposition, £99 a year or £29 a month as published on 5 September 2026, is the broader educational functionality: question banks with adaptive sequencing, the Socratic Tutor, the exam-date-aware planner, eighteen clinician-reviewed simulation tracks, and CPD records, together. A reader who only wants referenced clinical answers should stay on the free service and not subscribe.
A decision guide
Stay free: occasional reference use, a question a few times a week, general study through Study Mode, or a documentation need Heidi's free tier meets. Consider upgrading: a sustained learning goal, an examination in the next year, a recurring knowledge gap, a need for evidence of learning, where the paid features specifically address it. Try before deciding: iatroX's free question access and one complete free simulation exist so a reader can test the relevant feature before seeing the annual plan, and this guide recommends doing exactly that.
A worked decision for three readers
A foundation doctor who looks up two or three clinical questions a week and has no examination for eighteen months: stay free, Ask-iatroX for reference and Study Mode for the occasional concept, and revisit the decision when an examination date appears. A GP trainee eight months from the AKT with recurring weak topics: the paid features address the need directly, and a trial through the free question bank will show whether Tutor helps before committing. A PA student with the free PARA bank: stay free until the dashboard shows errors clustering on the same topics session after session, at which point tutoring on those errors is the specific thing worth paying for.
The honest test before paying
Try the feature the subscription is actually for. The free question bank demonstrates the adaptive sequencing; the free simulation demonstrates the transcript-linked feedback and remediation loop. If neither changes how you learn, the subscription will not either, and this guide would rather a reader discover that free than after paying.
Frequently asked questions
Is Ask-iatroX free only for a trial period?
No: it is an ongoing free service without a trial expiry or verification requirement.
Can UK clinicians use OpenEvidence free?
Its advertised free access is for verified US healthcare professionals; UK readers should check current eligibility rather than assume it.
What should a reader try before paying for iatroX?
The free question bank and one complete free simulation, which together demonstrate the tutoring and simulation the subscription is built around.