Frequently asked questions
Squiggler is an ECG generator for teaching. These are the questions people ask most.
What is Squiggler?
Squiggler lets you create ECGs that look exactly the way you want them to. Behind the scenes, the Squiggler engine models the heart, accounting for every part of it, including SA and AV node conduction, the electrical axis, amplitudes and the effects of age, to generate an ECG that not only looks real but is also physiologically plausible.
Are these real patient ECGs?
No. Unlike other “ECG simulators” that only redraw open-source waveforms, Squiggler builds every ECG from the ground up.
Who is it for?
Anyone who teaches ECGs: clinical educators, simulation teams, people writing exam and question-bank items, course organisers and medical schools. It is also used to make tracings for e-learning and simulation products.
What can it draw?
Open the studio and try it! Almost every type of ECG can be drawn, and findings can be stacked on top of each other. If you have an ECG showing atrial fibrillation, just add ST-segment changes to it, or change the rate to whatever you want. You can also split an ECG into sections to show something happening over time, for example atrial fibrillation converting to sinus rhythm.
Will the same settings always give the same ECG?
Yes. Every tracing is unique, but the same settings always reproduce it exactly. Even so, the possible variation is endless, because the tracings are procedurally generated.
Are the ECGs AI-generated?
No. Generative AI plays no part in drawing the image when you tune it. You can, if you like, use our AI Composer to get a matching ECG quickly from a description, and then fine-tune it yourself.
I have an e-learning or simulation platform. Can I use Squiggler tracings?
Yes, commercial platform use is supported. Contact inquiry@squiggler.io and we will get back to you. If you use Squiggler commercially, we are happy to look at how best to fit Squiggler’s capabilities to your product.
Can I use the tracings in exams, slides and published teaching material?
Yes. Because they are generated rather than copied from a textbook or a patient record, there is no third-party copyright or patient-consent problem.
What formats can I download?
PNG and JPG at screen, slide or print resolution, and PDF and SVG at true physical size, so a printout measures correctly. A Platform licence adds the raw waveform data (CSV or JSON) for simulators, as well as filters that make a tracing look scanned or photographed.
Is it free?
Yes. The studio is free to use, and downloads carry a small watermark. Unmarked exports, print sizes and more formats come pay as you go or with a plan.
Is there an API?
Yes. Our ECG engine is available through an API that draws a rhythm strip or twelve-lead from a description, which makes it suitable for generating question banks or for use by AI agents. If you develop a case or question-bank platform with an AI-first workflow, contact inquiry@squiggler.io and we will get back to you.
Can I use Squiggler ECGs for clinical decisions?
No. Squiggler is for education only.
Can I put an ECG case on my own website?
Yes. Every case in the ECG cases column comes with a one-line embed code, so it works inside your own page with a link back to Squiggler.
For education only; not for clinical use.