Pricing
If you have a weather station, a greenhouse or an Arduino on a windowsill, the free tier is the whole product as far as you are concerned — every tool on it, on your own files, with nothing stamped across the figures. It is not a trial and it does not run out. What money buys is the professional workflow: batches, censored data, and an export you can hand to a regulator.
Every licence is one payment. No subscription, no account.
Free
$0
forever
Import, resample, correlate and test a series for trend — on your own data, with no watermark and no account.
- Chart every channel
- 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
- One saved project, kept in this browser
- No account, no cookies, no upload
Pro
$49
one payment · 12 months
One payment. Twelve months of the professional workflow, then it lapses to free.
- Everything in Free
- Monitoring network trends
- Rolling correlation
- Gap & QC report
- Threshold & exceedance
- Batch runs across many wells or streams
- Censored-data methods and a report-ready export
- Saved projects, with no limit
- Batch export — every tool that fits your file, as one zip
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
$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.
- What happens after I pay?
- You come straight back here to a page showing your licence key, already applied to the browser you bought it in. Save it: there is no account, so the key is the purchase. Copy it, or download the licence file — a text file holding the key and the steps to restore it, which works with no internet connection. A copy is sent to the address you pay with as well, and re-opening that same page re-issues the identical key as many times as you need.
- 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.