How to make a line graph
- Enter your x-axis labels, such as dates, months, years or test numbers, in order in the first column.
- Enter the values for your first line in the next column. Click Add data series for each additional line, and rename the headers so the legend makes sense.
- Leave a cell blank if a value is missing. The line shows a gap instead of pretending the value is zero, and you can choose to connect across gaps.
- Under Customize, choose the line style, thickness, marker size and shape, and axis titles.
- Download in your preferred format. SVG and PDF keep thin lines crisp when printed.
Data format
| Column | Type | Notes |
|---|---|---|
| X-axis label | Text | Required |
| Data series (one column each) | Number | 1–12 columns; blank cells allowed |
Up to 500 rows. Each row is a point along the x-axis (a month, year, or step). Each value column is a separate line. Leave a cell blank to show a gap.
Customization options
- Straight, smooth or stepped lines. Smooth lines use monotone interpolation, so curves never overshoot your actual data points.
- Markers with a different shape per series (circle, square, triangle, diamond, cross), so lines can be told apart without color.
- Custom y-axis range or “start at zero”, plus axis titles and gridlines.
- Value labels on every point for small datasets.
- Gap handling: show blank cells as gaps or connect across them.
Downloading and exporting
- PNG: best for slides, documents and the web. It supports transparent backgrounds, and you can choose standard, 2×, 4× or slide-sized (1920 × 1080) output.
- JPEG: a smaller file with a solid background.
- SVG: a true vector file. It stays sharp at any size and can be edited in Illustrator, Inkscape or Figma.
- PDF: vector PDF sized to the chart, A4 or US Letter. If your labels use characters outside the standard PDF fonts (for example Chinese, Arabic or emoji), the PDF uses a high-resolution image instead and tells you.
- CSV and .json: your data, or the whole chart with its settings, to re-open later.
When to use a line graph
- Showing trends over time: monthly visitors, temperatures or stock prices.
- Comparing how several series move together over the same period.
- Any ordered sequence where the change between steps matters, such as dose levels or experiment iterations.
When to choose a different chart
- The x-axis categories have no natural order (products, countries). Lines would imply a progression that doesn’t exist; use a bar graph.
- You want to show how a total is composed over time. A stacked area chart shows the parts and the total.
- Both axes are measured variables and you are looking for a correlation. Use a scatter plot.
Common mistakes to avoid
Uneven time steps on an even axis
If your dates are irregular (Jan, Feb, Jun, Dec), each row still takes equal horizontal space. Either fill in the missing periods with blanks or make the irregular spacing clear in the axis title.
Too many lines
More than five or six lines creates “spaghetti”. Highlight one or two key series with strong colors and use a muted gray for the rest, or split the chart.
Zero-filling missing data
Typing 0 for an unknown value creates a false dip. Leave the cell blank so the line shows a gap.
Practical examples
Website traffic
Monthly unique visitors for two websites over eight months, shown as two lines with different marker shapes.
Temperature record
Daily highs and lows as two series. Use the smooth line style and turn markers off for long series.
Learning curve
Quiz attempt number on the x-axis and score on the y-axis. Turn on “Start y-axis at zero” if you want to show absolute rather than relative improvement.
Should a line graph start at zero?
Unlike bar charts, line graphs do not need a zero baseline. A line encodes change through slope and position, not length. Zooming in on the range where your data actually varies is often more honest: a body temperature chart that starts at 0 °C would hide a dangerous fever.
However, a heavily zoomed axis can exaggerate small changes. As a rule, include zero when the absolute size of the values matters to your message, and zoom in when the change is the message. Either way, label the axis clearly.
Frequently asked questions
How do I add multiple lines?
Click Add data series. Each value column becomes its own line, with its own legend entry and color. Rename the column header to name the line.
Can I use dates on the x-axis?
Yes. Type dates or periods as x-axis labels. Points are evenly spaced in the order you enter them, so enter one row per period and leave missing periods blank.
Why does my smooth line not overshoot the points?
We use monotone cubic interpolation, which never creates bumps above or below your real data. Some tools use curves that wiggle past the data and can suggest peaks that never happened.
Can I make a line graph with a second y-axis?
Use the Combination Chart Maker, which lets you assign any series to a right-hand axis and mix lines with bars.
What happens to blank cells?
They become gaps in the line. Turn on “Connect across blank cells” in Chart options to draw straight through them instead.
Your data stays private
Charts are drawn by your browser. Your data isn’t uploaded to our servers; it is kept only in this browser’s storage, for autosave and saved charts, until you clear it. See our privacy policy.