Pricing

One payment, no subscription, no account. The free tier is not a trial — it is the set of tools somebody with a weather station or an Arduino actually needs, in full, on their own data, with no watermark on anything.

Nothing is on sale yet. Checkout is not built. The prices below are decided and will not move when it is, and this page will stop saying this the day you can pay. Everything marked free below works right now.

Free

forever

Import, resample, correlate and test a series for trend — on your own data, with no watermark and no account.

Resample & aggregate
Mann-Kendall & Sen’s slope
Cross-correlation
ET₀ (FAO-56)
Chill hours & portions
Correlation matrix
VPD calculator
Dew point
Growing degree days
No watermark on any export
No account, no cookies, no upload

Pro

Coming soon

$49

one payment · 12 months

One payment. Twelve months of the professional workflow, then it lapses to free.

Everything in Free
Gap & QC report — not built yet
Batch runs across many wells or streams
Censored-data methods and a report-ready export

After twelve months the licence lapses and the free tools keep working. Nothing you have exported stops working, ever — the files are yours.

Founding licence

Coming soon

$119

one payment · never expires

One payment, no expiry, every future release.

Everything in Pro, with no expiry
Every tool added later

Limited to 199 licences.

What a licence does not do

It does not remove a watermark, because there is not one. Free exports are complete, unmarked, full-resolution figures. The sibling products in this family sell watermark removal; this one does not, because the free tools here are the traffic engine and a credit line stamped across a monitoring-report figure would simply send people somewhere else.

It does not unlock a result you can already see. Every Pro tool renders its sample dataset in full, for everybody, with every number visible — you can read exactly what it does before deciding whether it is worth anything to you. What a licence buys is running it on your files, in batch, with an export you can hand to a regulator.

It does not phone home. The key is verified in your browser against a public key built into the site, with no network call, which is why everything keeps working offline.

Already have a licence?

Paste it here. It is checked in this browser and stored on this device only.

Questions

Is this a subscription?: No. Both licences are a single payment. The $49 one covers twelve months and then lapses to the free tier; the $119 one never lapses. Neither renews automatically, because there is no account to renew against.
Do I need an account?: There is no account system. A licence is a signed string you paste into the box above, and it works on as many browsers and machines as you like.
Can I get a refund?: The free tier and the live sample on every Pro tool are a complete evaluation — you can see every number a tool produces before paying for it. So purchases are final. If something is broken, write to help@plotlad.com and it will get fixed.
What happens to my data?: Nothing. It never leaves your browser. The privacy page explains how to check that rather than take our word for it.