Function Grapher — Plot y = f(x) Online (Free)

Use this free function grapher to plot y = f(x) right in your browser. Type a function such as x^2-3 or sin(x), optionally add a second function and set the x-range, and the tool draws a clean, auto-scaled graph — no software to install.

How to use the function grapher

1. Type a function of x (you can use +, −, *, /, ^, parentheses, and functions like sin, cos, sqrt, ln, log).
2. Optionally add a second function and choose the x-range.
3. Press Calculate to see the curve, a table of sample values, and the plot.

Reading the graph

The grapher samples the function across your x-range, auto-scales the y-axis to fit, and draws the curve over a labeled grid. Points where the function is undefined are simply skipped, so you always get a clean plot.

Frequently asked questions

What functions can I graph?

Any expression in x using +, −, *, /, ^, parentheses, and sin, cos, tan, sqrt, ln, log, abs and exp, plus the constants pi and e.

Can I plot two functions at once?

Yes — enter a second function g(x) and both curves are drawn together in different colors so you can compare them.

How is the y-axis scaled?

Automatically: the grapher samples your function over the x-range and fits the y-axis to the values it finds.

Read the full lesson: learn the method step by step.