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Graphing Calculator

f(x)= Equation preview
Hover over graph
Special Keys
Trigonometric Functions
Move mouse over graph

Free Online Graphing Calculator – Plot & Analyze Mathematical Functions

Plot a function when a table of numbers is not enough to show its shape. Enter an expression in x, such as x^2 + 2*x - 1, then draw it on the coordinate grid. Add another graph to compare shapes, inspect values by hovering, pan the view, adjust each axis, or download the current graph image.

The graph is a visual aid, not a proof of an exact intersection, root, maximum, or discontinuity. Zooming can make features easier to see but does not increase the calculation precision. Use the coordinates and a separate calculation to verify values that need to be exact.

New to reading graphs? See How to Read a Function Graph: Intercepts, Slope, and Shapes.

Function Graphs

Plot standard mathematical functions such as y = x², y = sin(x), y = log(x), and more complex expressions.

Multiple Graphs

Draw multiple equations on one set of axes to compare their shapes and visually investigate where they may meet.

Plain Text Input

Enter equations using plain text notation. They're automatically converted into formatted mathematical notation.

Interactive Zoom

Zoom in and out independently on both X and Y axes to explore graph details at any scale.

Coordinate Tracking

Hover over the graph to see exact Y values for different X positions with point highlighting.

Download Graph

Export and download your graph as an image for use in reports, presentations, or homework.

How to Use the Graphing Calculator

  1. Enter your equation in plain text format (e.g., x^2 + 2*x - 1)
  2. View the formatted equation in the preview area
  3. Click Draw to plot the graph
  4. Add more equations using Add New Graph
  5. Hover over the graph to see exact coordinate values
  6. Zoom in or out to explore details
  7. Download the graph as an image if needed

Good to Know When Plotting

  • Write multiplication explicitly. Use 2*x rather than 2x so the expression is read correctly.
  • A plotted curve is a visual estimate, not proof of an exact root, maximum, or intersection.
  • Zooming reveals detail but does not increase the precision of a value you read off the graph.
  • Compare functions by adding more than one equation to the same axes.
  • Download the view as a PNG for reports, slides, or homework.
  • Need exact roots or symbolic steps? Use the Equation Solver.

Frequently Asked Questions

Why does my equation not plot?

Check that multiplication is written explicitly (use 2*x, not 2x) and that every parenthesis is closed. The preview area shows how your input was interpreted.

Can I plot multiple graphs at once?

Yes. You can draw multiple equations on the same graph for comparison.

How do I enter equations?

Enter equations in plain text format. They will be automatically converted into mathematical notation.

Can I download the graph?

Yes. You can export and download the graph as an image.

Does a visible crossing prove an exact intersection?

No. A crossing is an estimate from the rendered graph. Use the displayed coordinates or solve the relevant equations separately when you need an exact value.

About VioApps

This graphing calculator is part of VioApps, a browser-based collection of math and productivity tools. We built it so students and engineers can plot equations and inspect functions without installing dedicated software. All plotting happens locally in your browser.

Fast & Light

No downloads required

Secure

Your data stays private

Responsive

Works on all devices

Have any questions, suggestions, complaints, or feedback about our apps? We'd love to hear from you! Send us an email at support@viotools.com