Pricing

Free to use. Pro to publish.

Every diagram and every QA check are free. Pro simply removes the watermark and unlocks data export.

Free

$0
  • All seven diagram types (Piper, Stiff, Schoeller, Chadha, Durov, Gibbs, bivariate)
  • Charge-balance QA and water-type classification
  • TDS, hardness, SAR and RSC computed automatically
  • Editable data grid and full colour control
  • SVG & PNG export (with a small “TRIAL” watermark)
Open the plotter
Available now

Pro

$29 / year
  • Everything in Free
  • Clean, watermark-free figures on screen and in exports
  • CSV export of your cleaned data and computed indices
  • Priority on new diagram types and features
  • Supports ongoing development
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Questions
Pricing & billing
Is the free version time-limited?

No. The free tier is a permanent, fully working tool — not a trial that expires. The only thing Pro changes is the watermark and data export.

What exactly does Pro remove?

The faint “TRIAL” watermark across each diagram (on screen and in your SVG/PNG exports), and it unlocks CSV export of your cleaned data and computed indices.

How will payment and tax work?

Pro is sold through Polar, a merchant-of-record, which means GST/VAT and sales tax are handled and shown on your receipt automatically — you won’t need to deal with cross-border tax yourself.

Will my data ever be uploaded?

No. Free or Pro, every calculation happens in your browser. Your analyses are never sent to a server. See the About page for detail.

Can I use the figures in reports and publications?

Yes. Free exports carry the watermark; Pro produces clean, publication-ready figures.