Plotline

Graph it. Slide it. Understand it.

Type a function and watch it draw. Any letter like a or k becomes a slider you can animate, and roots, intersections, slopes and areas are a tap away.

Start graphing See how it works

Free, no sign-up Saved on your device Share any graph with a link

Your graph Saved

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Insert Inserts at the cursor. Typing ^, sqrt and pi works too.

Sliders

Use a letter like a, b or k in a function, for example a·sin(bx), and a slider appears here.

Drag to pan · scroll or pinch to zoom · arrow keys and + − when focused

Type. Slide. Tap.

Three moves take you from a formula to an answer.

Type a function

Write it the way you would on paper: 3x^2 − 2x, sin(2x), sqrt(x), |x|. Mistakes are pointed out as you type.

Slide the letters

Any extra letter, like a in a·sin(x), becomes a slider. Drag it or press play and watch the curve move.

Tap for answers

Roots, turning points and intersections are marked on the graph. Pick a point for its slope, or two bounds for the area.

A real grapher, in a tab.

Everything you reach for in a maths class or a lab report, without installing anything.

Every letter becomes a slider.

Type a·sin(bx) and get sliders for a and b, with editable range and step. Press play to animate at 60 frames a second.

(2, 4)

Intersections, found for you

Every crossing between visible curves is marked and listed.

∫ = 9

Area in one tap

Shade a definite integral and read its value to seven figures.

Tangent at any point

f(a), the slope f′(a) and the tangent line, live as you drag.

Asymptotes done right

No fake vertical lines through tan(x) or 1/x. The pen lifts at every break.

Errors that point at the problem.

Plotline says what is wrong and where, and underlines the exact part to fix.

Table of values

Pick a start and a step. Copy it as CSV for a spreadsheet.

x	f(x)
0	0
1	1
2	4
3	9

Export a crisp PNG

At twice the screen resolution, with a legend of every function and slider value. Ready for a report or a slide.

Links that rebuild the graph

Functions, colours, slider values, the view and every overlay live in the link. Send it and they see exactly what you see.

Questions

What can I type?

Numbers, x, + − * / and ^ (or **), brackets, pi or π, e, and the functions sin, cos, tan, their inverses (asin or arcsin), sinh, cosh, tanh, sec, csc, cot, sqrt, cbrt, abs or |x|, ln, log (base 10), log2, exp, floor, ceil, round, sign, min, max and pow. Multiplication can be implied, so 2x, 3sin(x) and 2(x + 1) all work. You can also start with y = or f(x) =.

How do sliders work?

Any single letter other than x and e is a parameter. The first time you use one, it gets a slider from −10 to 10 with a step of 0.1. Change the range and step to suit, or press play to sweep it back and forth. A letter shared by two functions is the same slider in both.

How accurate are the numbers?

Integrals use Simpson's rule with 4,000 intervals, roots and intersections are refined by bisection to about 13 significant figures, and slopes use a central difference. For smooth functions the results match exact answers to well beyond the digits shown.

Where is my graph saved?

In your browser's storage on this device. Nothing is uploaded, and there is no account. Your last graph is there when you come back.

How do I share a graph?

Use Copy link. The link holds your functions, colours, slider values, view and overlays, so whoever opens it sees the same graph. Export PNG saves an image with a legend instead.

Does it work on a phone?

Yes. Pinch to zoom, drag to pan, and use the insert row for symbols like √, π and |x| that are awkward on a phone keyboard.