A free GraphPad Prism alternative for bioassay data
If you analyse ELISA plates, dose-response curves, enzyme kinetics or ecotoxicological risk indices, you do not need a licence to do it properly. This page compares Labreador with GraphPad Prism and Excel — honestly, including where Prism is still the better tool.
No licence cost
Every module is free, with no seat limits, trials or export paywalls.
Minutes, not spreadsheets
Paste the reader export, assign the platemap, fit the curve, export the report.
Data never leaves the browser
All computation is client-side, which also means it works offline.
Labreador vs GraphPad Prism vs Excel
| Feature | Labreador | GraphPad Prism | Excel |
|---|---|---|---|
| Price | Free, no account | Paid annual licence | Part of an Office licence |
| Installation | None — runs in the browser (installable PWA) | Desktop install per seat | Desktop install |
| 4PL / 5PL curve fitting | Built in, with automatic model selection | Built in | Manual Solver setup or add-in |
| IC50 / EC50 with 95% CI | Yes, with extrapolation flags | Yes | Approximation only |
| Interactive platemap (48/96/384) | Yes, with drag selection and replicate groups | No plate layout view | Manual grid |
| Method health checks (CV%, recovery, OD span) | Automatic panel | Manual setup | Manual formulas |
| Parallel Line Analysis (Ph. Eur. 5.3) | Dedicated module | Possible, manual | Impractical |
| Ecotoxicology indices (Igeo, THQ, BSAF, BAF) | Dedicated module | Not included | Manual formulas |
| Statistical group comparison and post-hoc tests | Yes, automatic test selection | Yes, extensive | Limited |
| Where your data is processed | Locally in your browser — nothing uploaded | Locally on your machine | Locally or in cloud storage |
| Citable validation record | Zenodo DOI + peer-reviewed method paper | Vendor documentation | None |
| Best for | Routine bioassay and ecotox analysis, fast and reproducible | Broad general-purpose biostatistics and figures | Ad-hoc tables and simple plots |
Comparison reflects typical use for plate-based bioassay workflows. Third-party product capabilities and pricing change — check the vendor documentation for current details.
Where Labreador is the faster choice
Plate-native workflow: an interactive 48/96/384 platemap with drag selection, replicate groups and blank handling.
Assay validity is checked for you: R² tier, replicate CV%, back-calculated standard recovery, OD span and EC50 position with 95% CI.
Specialised modules that general statistics packages do not ship: Parallel Line Analysis to Ph. Eur. 5.3 and a full ecotoxicology suite.
Reproducible and citable: a Zenodo DOI per release plus a peer-reviewed method description.
Nothing to install or approve by IT — it opens in a browser and can be installed as an offline app.
Where Prism still makes sense
You need a very wide range of statistical tests across many project types, not only bioassay data.
Your lab has standardised figure templates and workflows already built in Prism.
You require vendor support contracts or a validated desktop deployment mandated by your QA system.
Frequently asked questions
Is Labreador a full replacement for GraphPad Prism?
Not for everything. Prism is a broad general-purpose statistics and figure package. Labreador focuses on bioassay workflows — ELISA quantification, dose-response IC50/EC50, kinetics, parallel line analysis and ecotoxicology — and does those end to end for free. If your work is mainly plate-based quantification, Labreador usually covers it; if you need every statistical test and journal figure style in one desktop app, Prism still has a wider scope.
Is there a free alternative to GraphPad Prism for ELISA?
Yes. Labreador fits 4PL and 5PL standard curves, back-calculates the standards, reports replicate CV%, recovery and LLOQ/ULOQ flags, and exports CSV or PDF — with no licence and no account.
Why not just calculate ELISA or IC50 in Excel?
Excel has no native sigmoidal regression, so most spreadsheet workflows use log-linear or point-to-point interpolation, which biases the ends of the curve. Blank correction, dilution factors and replicate statistics are also easy to break when formulas are copied between sheets, and nothing checks whether the curve is valid.
Is my data safe if it runs in a browser?
All calculations run client-side. Your plate values are never sent to a server, which is why the app also works offline once installed.
Can I cite Labreador in a publication?
Yes. Each release has a Zenodo DOI, and the underlying method is described in a peer-reviewed article — both are linked from the Tool Validation button in the footer.
Prefer a quick overview first? Read the .