Browser Choice

The graphing calculator runs fastest in a Chromium-based browser such as Chrome or Edge. In Firefox, and possibly in Safari, it works the same way but feels slower. This page explains why, so the notice the calculator shows is not a mystery.

How a graph reaches the screen

Every graph you open shares one set of graphics machinery: one WebGL context, one set of compiled shaders, one set of render buffers. Creating that machinery is the slow part of graphing, so the calculator creates it once and keeps it for the life of the page instead of building a fresh copy for every graph tab.

To make that sharing possible, the machinery does not draw onto the canvas you see. It draws into an offscreen canvas, and when a frame is finished the browser hands the finished image over to the tab's visible canvas. That hand-off happens on every frame: every pan, every zoom, every slider move.

Where the difference comes from

• The hand-off. In a Chromium-based browser the finished image stays on the graphics card and the hand-off is close to free. In Firefox, and possibly Safari, the image is copied back through the processor on its way to the visible canvas. At a full-screen resolution that copy can take longer than drawing the graph did, and it is paid on every frame.
• Shader compilation. Each expression you graph is compiled into a small program for the graphics card. Chromium-based browsers support compiling those programs in the background, so the page stays responsive while a new expression compiles. Firefox does not support background compilation, so the page pauses until the compile finishes. A complicated expression can pause it for a noticeable moment.

Neither of these is something the calculator can work around from its side. They are properties of the browser's WebGL implementation.

What to do

If you notice the graph lagging while you pan or zoom, or a pause each time you add an expression, open the same graph in a Chromium-based browser. Your account, your saved graphs and any link you have shared work identically in every browser; only the speed differs.

How the calculator decides to show the notice

The calculator does not look at the browser's name. It checks whether background shader compilation is available and measures how long the hand-off of a finished frame actually takes on your machine. The notice appears only when one of those comes out poorly. Dismissing it hides it for the rest of your session.