Your data
Paste a table straight from Excel or Google Sheets, or drop a CSV file. Nothing is uploaded anywhere — the whole calculation runs inside this browser tab.
CSV, TSV or plain text. Files saved in windows-1251 are detected and re-read automatically, so Cyrillic headers do not turn into garbage.
Parsing options
Columns
Result
Save and share
The drawing library is downloaded only when you press the button, and only on this page.
This page has no server side at all. The table you paste is parsed by JavaScript inside your own browser, the chart is drawn on a canvas element on your machine, and the export file is assembled locally. Nothing is uploaded, stored or written to any log. You can disconnect from the network after the page has loaded and everything will still work — which is the simplest way to verify the claim yourself.
Facts and limits of this method
| Best for | A single quantity measured repeatedly over time |
|---|---|
| Minimum rows | 2 — but a line through two points carries no more information than a sentence |
| Comfortable range | 5 to 400 points; beyond that the markers are hidden automatically |
| Axis requirement | The horizontal axis must have a natural order. Alphabetical categories do not. |
| Zero baseline | Not required. Unlike bars, a line encodes change, not magnitude. |
| Output | PNG at 2× scale, plus CSV, JSON and Markdown of the underlying data |
When it misleads you
- The slope you see depends entirely on the aspect ratio of the picture. Stretch the same data horizontally and a dramatic collapse turns into a gentle slide — this is the single most common way line charts mislead.
- Connecting points with a line claims that intermediate values existed. For monthly revenue that is fine. For a survey run in March and then in November, the line invents eight months of data you never collected.
- Gaps in the data are drawn straight through by default, which quietly hides the fact that a period is missing entirely.
- With more than four or five lines the chart becomes a plate of spaghetti and nobody can trace a single series. Split it or switch to small multiples instead.
How it is calculated
Every row becomes one point. The label column supplies the text under the horizontal axis and the numeric column supplies the height. Rows whose numeric cell is empty or non-numeric are drawn as a gap rather than as zero, because a missing measurement and a measurement of zero are different facts.
The vertical axis is scaled to the data, not forced to start at zero. That is deliberate and it is the standard convention for lines: the eye reads the slope, not the area under it, so cropping the axis does not exaggerate anything the way it does with bars. If you need the zero baseline for an audience that expects it, a bar chart is the honest alternative.
Numbers are parsed with both decimal conventions in mind. "1 234,56", "1,234.56" and "1234.56" all become the same value, and currency symbols and percent signs are stripped, because that is how tables actually arrive from accounting software.
The curve is drawn with a slight tension so it reads as a trend rather than a zigzag, but it never overshoots the real points: the line always passes exactly through every value you supplied.
Questions and answers
Is my file uploaded anywhere?
No. The page has no server component at all. The parsing, the drawing and the PNG export all happen in JavaScript inside your browser. You can load the page, disconnect from the internet, and every function still works.
Can I use a semicolon-separated file from a Russian or European Excel?
Yes. The delimiter is detected automatically, and if the guess is wrong you can pick comma, semicolon or tab manually under "Parsing options". The decimal comma is handled there too.
My CSV has Cyrillic headers that turn into question marks. What do I do?
Nothing — the file is re-read as windows-1251 automatically when the UTF-8 pass produces replacement characters. That covers almost every CSV exported by a Russian version of Excel.
How do I get the chart into PowerPoint or a document?
Use "Copy image" and paste it directly, or "Download PNG" if you prefer a file. The PNG is rendered at double resolution with a white background, so it stays sharp when projected and does not turn into a black rectangle in dark mode.
Can I plot several lines at once?
This page draws the first numeric column. For several series on one canvas use the multi-series version, which is linked at the bottom of the page.