The analysis workbench for sensor time-series data
You have a file of readings from a logger, a weather station, or a sensor you wired up yourself. Drop it in and get charts, averages and answers out of it — with no install, no account, and no code.
Your file never leaves your browser. The button opens the first tool, and every other tool here reads the same file.
All 14 tools below work today. Nothing here is a mock-up: if a page says a tool works, the arithmetic runs.
Start with one of these
The three most people want first. Each one opens with real data already loaded, so you can see what it makes before you go and find your own file.
Average your file by hour, day or month. The band behind the line shows the highest and lowest reading the average covered up.
Resample & aggregate
A coloured grid of every channel against every other one. Blue means they rise and fall together; orange means one goes up as the other goes down.
Correlation matrix
Turn temperature and humidity into a dew-point line, and mark every spell where the air reached the point of condensing.
Dew point
Weather, water and growing
The everyday numbers a grower or a weather station owner needs. Each one is worked out across your whole file, not from one reading you type in, and each figure names the formula it used.
Daily water use for a reference crop, worked out from your station file by the FAO-56 method.
ET₀ (FAO-56)
Vapour pressure deficit over your whole record, for the air and for the leaf.
VPD calculator
Growing degree days from your own temperatures, by the simple average or the single-sine method.
Growing degree days
Winter chill from an hourly temperature file, counted three ways at once, because the three ways disagree.
Chill hours & portions
Is it really changing?
A line that wanders is not the same as a line that is going somewhere. These two tell those apart, and find which of two sensors moves first.
The Mann-Kendall trend test and Sen’s slope on one series, with values below the detection limit kept rather than dropped.
Mann-Kendall & Sen’s slope
Slide one series past the other and read off the delay where they line up best — how leaf wetness follows humidity by about two hours.
Cross-correlation
For people who do this for a living
Bigger jobs: a whole monitoring network at once, and the checks a report has to survive. Each of these opens with a worked example anyone can read. Running your own file through one needs a licence, and licences are not on sale yet.
The same trend test across a whole monitoring network, with a report-ready matrix.
Monitoring network trends
The correlation between two channels, window by window, instead of once overall.
Rolling correlation
Every outage, flatline and jump in a record, plus the completeness figure for a methods section.
Gap & QC report
Frost hours, heat hours and exceedance events — with time the logger missed reported as unknown.
Threshold & exceedance
Everything else
Also in the catalogue.
Chart every numeric column of a logger file together — grouped onto two y axes by unit, or scaled to a common range — with the gaps drawn as gaps and the thinning stated.
Chart every channel
What this site promises
Your file stays on your machine
There is nowhere to upload it to. The site is static files, and the maths runs in your tab. Load the page, unplug the network, and keep working. How to check that
It reads logger files as they come
HOBOware and Postlad exports are recognised on sight, along with plain CSV, TSV and Excel files. You should not have to tidy a file up first.
It tells you what it hid
Averaging throws readings away. Every average here also shows the highest and lowest reading behind it, and a gap in your data is drawn as a gap.
Before you trust it
Three things a careful reader asks before putting a figure in a report.
Is the arithmetic right?
Worked examples from FAO-56, Gilbert, the EPA and NIST, put beside what this site works out — each with the test that checks it named underneath.
Will it read my logger file?
What each export really looks like, and which of its oddities are handled: HOBO, Campbell TOA5, METER ZENTRA, Lascar EasyLog.
I already use something else
What the other thing is better at, and the one job it does not set out to do: Grafana, ThingSpeak, or desktop trend-testing software.
Where the readings come from
This site works on files. If you are still walking out to a logger with a laptop, its companion — Postlad, at postlad.com — takes a reading straight from an Arduino or an ESP32 and gives you a live chart and a share link, with no account.
Already have a stream?Paste a Postlad CSV export link into the Open page and your browser reads it straight from Postlad into the tool — nothing goes through us. It needs Postlad to allow the read; if it does not, the page tells you and takes the downloaded file instead.
Pricing here will be a one-time $49 for twelve months or $119 for a founding licence. Neither is on sale yet, and everything marked free stays free.