gratia
gratia: A focused R toolkit for visualizing, diagnosing and comparing GAM smooths. Ranked #64 of 106 in Statistical Analysis Software by our editors (3.0/10); pricing: Free plan; best for R users analyzing and comparing GAM smooths.
At a glance
- Editor score3.0 / 10
- PricingFree plan
- Best forR users analyzing and comparing GAM smooths
- Free planYes
- Paid fromFree
- DeploymentDesktop
- Facts checked24 Sep 2026
Where it wins
- Plots estimated GAM smooths with ggplot2-based graphics
- Supports derivatives, confidence intervals and posterior samples
- Compares smooths across models and creates diagnostic plots
Where it doesn't
- Focused on GAM workflows rather than general-purpose statistics
- Works as an R package, not a standalone hosted analysis service
- Primarily targets models fitted with mgcv
Our verdict on gratia
For analysts working with generalized additive models in R, gratia provides tools to explore and visualize fitted GAMs, primarily models fitted using mgcv. It is aimed at people who need more than a model fit: its functions cover smooth-term plots, derivatives, confidence intervals, posterior samples and diagnostics. The package is open source and supports Windows, macOS and Linux. This focus makes it relevant to R users comparing GAM smooths, but not a replacement for a general-purpose statistical analysis environment.
Its strongest fit is the GAM workflow around smooth terms. Gratia produces ggplot2-based plots and tidyverse-compatible representations of estimated smooths, and it can calculate point-wise and simultaneous confidence intervals. Analysts can also estimate smooth-term derivatives, generate posterior samples, extract fitted values, residuals and model terms, and create diagnostic plots for fitted models. Functions for comparing smooths across models extend the package beyond inspecting a single fit. These features make it useful when interpretation and comparison of GAM terms are central to an analysis, rather than broad statistical testing across many model types.
The ecosystem fit is specifically R, with integrations for mgcv, ggplot2 and tidyverse. Gratia is a package to add to an R-based analysis workflow, not a standalone hosted service, so it suits users already working with R and GAMs better than teams seeking a separate point-and-click statistics product. Its open-source model and documentation and community support channels are relevant to adoption; the package's narrow focus is also its main boundary. Choose gratia for GAM smooth exploration, derivatives, diagnostics and model comparisons in R. Choose a broader statistical suite if your primary need is analysis beyond GAM workflows.
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gratia pricing
gratia fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Deployment | Desktop |
| Statistical tests | Yes |
| Regression models | Yes |
| Scripting support | Yes |
| Bayesian analysis | Yes |
| Data import formats | Not verified |
| Deployment | Desktop |
| Platforms | Windows, macOS, Linux |
| Support | Docs, Community |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 3 integrations: mgcv, ggplot2, tidyverse |
| Pricing | Free plan |
| Website | gavinsimpson.github.io |
| Facts checked | 24 Sep 2026 |
gratia integrations
gratia lists 3 integrations on its own site.
- mgcv
- ggplot2
- tidyverse
Alternatives to gratia
- RA free, programmable environment for statistical analysis, modeling, visualization, and data import.9.4
- StataA broad, scriptable desktop environment for professional and reproducible applied analysis.9.3
- IBM SPSS StatisticsA broad desktop statistics suite with testing, modeling, forecasting, reporting, and R/Python integration.9.2
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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