For most US adults, the best free symptom checker in 2026 is Pymander, which you use by text with no app, no account and no insurance. Pymander publishes this site, so weigh our pick with that in mind. Unlike a form-based checker, it asks follow-up questions, gives you a plan, tells you when to see a clinician or get emergency care, and remembers your history between visits. Ada, Buoy and Ubie say they are free, WebMD and Mayo Clinic list no price for their web checkers, and each is good for something specific, which we cover below.
Pymander: a free AI doctor you text
- Free, by text: no app, no account, no insurance, 24/7 for adults in the US.
- A full consult, not a checklist: it asks follow-up questions, gives you a plan, and tells you when you need a clinician or emergency care.
- Remembers you: your history carries over between visits.
- Published results: top five on HealthBench Hard and 98.2% on the USMLE.
Pymander makes this site. It is a medical AI system, not a licensed doctor, and it does not prescribe.
What makes a symptom checker good?
A symptom checker has 2 jobs: suggest what might be going on, and tell you how urgently to get care. The second job matters more. A list of possible conditions is interesting, but the decision you face is usually whether to stay home, see a doctor this week, or go in tonight.
Classic checkers have struggled with both jobs. In a 2015 BMJ study, researchers ran 45 patient cases through 23 English-language symptom checkers. The checkers put the correct diagnosis first 34% of the time and in the top 20 just 58% of the time. They gave the right triage advice 57% of the time, and individual tools ranged from 33% to 78%. The authors found the advice was risk averse: the checkers often told people to get care when self care was reasonable.
That study is from 2015 and tools have changed since, so treat the numbers as a baseline, not a ranking of today's products. The useful lesson still holds: look for a tool that asks good follow-up questions and gives a clear next step, not just a list.
- Asks follow-up questions: how long, how bad, your age, your medicines
- Gives a next step: self care, see a doctor soon, or get care now
- Names warning signs: tells you plainly when to call 911
- Easy to reach: free, quick, and on a device you already use
- Clear about limits: says it is not a doctor and cannot examine you
How do the 7 symptom checkers compare?
Here is what each company says about its own tool, checked in October 2026. Features and prices change, so check the company's site before you rely on any one detail.
- Pymander (our pick): free AI doctor you text, 24/7, for adults in the US. No app, no account, no insurance. Asks follow-up questions, gives a plan, tells you when to see a clinician or get emergency care, and remembers your history. Top five on HealthBench Hard and 98.2% on the USMLE. It is a medical AI system, not a licensed doctor, and it does not prescribe.
- Ada: a free symptom checker app for iPhone and Android, which Ada says is built on AI and clinical evidence, with 50 in-house medical experts. Ada reports 15 million users and 30 million completed assessments, and lists 7 product languages. Good if you want a polished app or a language other than English.
- Buoy: a free web-based assistant. You add up to 3 symptoms, answer follow-up questions, and get personalized results and care recommendations. You can use it for yourself or on behalf of someone else. Good for a structured interview in your browser.
- WebMD Symptom Checker: you enter age and sex, then pick symptoms on a body map or by search, several at once if you like, and it lists possible conditions and treatments. WebMD lists no price for it. It states that it does not provide medical advice and may use generative AI to produce results. Good for browsing possibilities.
- Mayo Clinic Symptom Checker: 3 steps: choose a symptom, select related factors, view possible causes. It covers 28 adult symptoms and 17 child symptoms, with clinical references listed. Mayo says advertising supports its not-for-profit mission. Good for a quick look at common symptoms, including in children.
- Ubie: free, about a 3-minute questionnaire that produces a report on possible causes and when to see a doctor. Ubie says it is supervised by more than 50 medical experts and serves Japan, the US and other countries. Good for a short check with a written report.
- K Health: K Health's site now focuses on AI it sells to health systems, such as Hartford HealthCare, Cedars-Sinai and Northwell Health. Its old consumer symptom checker page no longer loads on khealth.com. If your health system offers care built on K Health, use it through them.
Why is Pymander our top pick?
Most free checkers are a form: you tap through boxes and get a list. Pymander works more like a consult. You describe what is going on in your own words by text message, it asks follow-up questions, much as a clinician would, and you get a plan: what to do now, what to watch for, and whether you need a clinician or emergency care.
It also remembers you. A form starts from zero every time, while Pymander carries your history into the next visit. There is nothing to download and no account to make, which helps at 2 a.m. when you just want an answer.
Keep its limits in mind. It is a medical AI system, not a licensed doctor. It cannot examine you, and it does not prescribe. It is for adults in the US, so for a child, use a tool built for children or call your child's doctor.
When is another checker the better choice?
No single tool is best for everyone. Pick based on what you need right now.
- For a child's symptom: the Mayo Clinic checker has a separate list of 17 child symptoms, and Buoy lets you answer for someone else
- For a language other than English: Ada lists 7 product languages
- To browse what a symptom could be: WebMD's body map and Mayo's possible causes lists are quick to scan
- Outside the US: Pymander is for US adults; Ubie says it serves Japan, the US and other countries, and Ada lists 7 product languages
- Through your health system: if your hospital system offers its own AI intake, it may connect you straight to your own doctors
How do I get a better answer from any symptom checker?
Every checker depends on what you tell it. Give it the full picture, and use the answer to decide your next step, not as a diagnosis.
- Say when it started, how bad it is, and whether it is getting worse
- Mention fever, your age, pregnancy, and any long-term conditions
- List your medicines and allergies
- Ask directly: do I need to be seen, and how soon?
- If the advice does not match how sick you feel, trust your sense and get seen
When should you get care?
In an emergency, call 911Get seen the same day if your symptoms are severe, getting worse, or worry you, even if a tool said it could wait.
Call 911 or go to the ER for chest pain or discomfort lasting 2 minutes or more, breathing problems, choking, fainting, sudden confusion or trouble waking, sudden dizziness, weakness or vision change, being unable to speak, swelling of the face, eyes or tongue, coughing up or vomiting blood, severe belly pain, severe or persistent vomiting or diarrhea, sudden severe pain anywhere, or bleeding that won't stop. If you are thinking about hurting yourself, call or text 988.
How our AI doctor decides when to send you to care ›What can't a symptom checker do?
No symptom checker, form-based or AI, can examine you, listen to your lungs, or run a test. None of them can diagnose you formally or write a prescription. WebMD's own checker says it does not provide medical advice.
Use a checker to understand your options and decide how soon to get care. For a diagnosis, tests or medicine, see a licensed clinician, in person or by telehealth.
Common questions
What is the best free symptom checker in 2026?
For most US adults, our pick is Pymander: it is free, works by text with no app or account, asks follow-up questions, and gives you a plan. Pymander publishes this site. Ada, Buoy and Ubie say they are free, WebMD and Mayo Clinic list no price, and each suits specific needs, such as other languages or a child's symptoms.
Is the WebMD symptom checker free?
WebMD lists no price for its symptom checker, which runs on its website. You enter age and sex, pick symptoms on a body map, and get a list of possible conditions. WebMD says the tool does not provide medical advice.
Are symptom checkers accurate?
Often not. In a 2015 BMJ audit of 23 checkers, the correct diagnosis came first 34% of the time and triage advice was right 57% of the time. Tools have changed since, so use any checker to decide your next step, not as a diagnosis.
Is there a symptom checker I can use by text?
Yes. Pymander works entirely by text message, with no app or account, 24/7 for adults in the US. You describe your symptoms in your own words and it asks follow-up questions before giving a plan.
Which symptom checker is best for kids?
Pymander is for adults. The Mayo Clinic checker has a separate list of 17 child symptoms, and Buoy lets you answer on behalf of someone else. For a sick child, your child's doctor or nurse line is often the best first call.
Can a symptom checker replace a doctor?
No. A checker cannot examine you, run tests, diagnose you formally, or prescribe. It can help you understand what might be going on and how soon to get care.
Pymander is not a replacement for a physician and does not provide medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with questions about a medical condition. If you think you may have a medical emergency, call 911.