Built for cell & gene therapy and biologics potency. Paste your curves → relative potency with a Fieller CI, equivalence-based parallelism (USP <1032>), 4PL fits with real covariance confidence intervals, and a Certificate of Analysis — no install, no upload, flat-rate.
Free to try · fits entirely in your browser · nothing you fit is uploaded on its own
Live output: 4PL fit · 95% CI band · EC50 marker · published-potency overlay from ChEMBL.
Most fitters give you a number and a line. DoseFit gives you the number, how sure it is, and — for potency — relative potency and parallelism the way a regulator expects it. In the browser, flat-rate.
Joint common-shape fits, relative potency with a Fieller CI, and equivalence-based parallelism (USP <1032>/<1034>) — the modern method, not the over-sensitive F-test. Compare CAR-T constructs or lots the way a reviewer expects.
Parameter-covariance confidence intervals (Prism/R-standard, not optimistic), constrainable plateaus, and honest warnings when your EC50 is an extrapolation — with a residual-bootstrap cross-check.
One-click Certificate of Analysis (print to PDF) with results, QC verdict and method — plus publication-ready 2× PNG or vector SVG with the confidence band and EC50 marker.
Overlay the published potency distribution for a target (live from ChEMBL) and see exactly where your compound lands. And no install — it runs on any laptop or phone.
One dose, response per line — comma, space, or tab separated. Pick your dose unit.
10, 5 100, 38 1000, 93Get EC50 / IC50, Hill slope, plateaus and R² — each with a 95% confidence interval and a shaded band, computed right in the browser.
Pick a reference to get relative potency + parallelism, overlay the published range from ChEMBL, then download a CoA or a publication-ready PNG / SVG. Read the guide →
The fitter runs entirely in your browser — the data you paste and fit is never uploaded on its own. A few features use the network only when you choose them: ChEMBL comparison (sends just a target ID), AI-interpret (opt-in), and cloud save (Pro). For a lab handling sensitive results, that default is the point. Read the privacy note →
The fitter is free, forever. Paid tiers add accounts, saved methods, and compliant reporting as your lab needs them.
The full browser tool.
For working scientists.
For regulated labs.
No sign-up. Load an example or paste your own data.