How do you get p5.js into a website?

Follow these instructions: http://p5js.org/get-started/

Or these instructions: https://github.com/processing/p5.js/wiki/Embedding-p5.js

In other words, you need to create an html file that uses p5.js, which you should already have.

Then you need to upload that html file, along with any resources you're using, to some kind of web host.

You might also want to check out Processing.js, which comes with the standard Processing editor.


creat html file and a sketch.js file

in your html file you can put in a starter template and then add p5js in the sketch.js

check the docs here

// All the paths
var paths = [];
// Are we painting?
var painting = false;
// How long until the next circle
var next = 0;
// Where are we now and where were we?
var current;
var previous;

function setup() {
  createCanvas(720, 400);
  current = createVector(0,0);
  previous = createVector(0,0);
};

function draw() {
  background(200);
  
  // If it's time for a new point
  if (millis() > next && painting) {

    // Grab mouse position      
    current.x = mouseX;
    current.y = mouseY;

    // New particle's force is based on mouse movement
    var force = p5.Vector.sub(current, previous);
    force.mult(0.05);

    // Add new particle
    paths[paths.length - 1].add(current, force);
    
    // Schedule next circle
    next = millis() + random(100);

    // Store mouse values
    previous.x = current.x;
    previous.y = current.y;
  }

  // Draw all paths
  for( var i = 0; i < paths.length; i++) {
    paths[i].update();
    paths[i].display();
  }
}

// Start it up
function mousePressed() {
  next = 0;
  painting = true;
  previous.x = mouseX;
  previous.y = mouseY;
  paths.push(new Path());
}

// Stop
function mouseReleased() {
  painting = false;
}

// A Path is a list of particles
function Path() {
  this.particles = [];
  this.hue = random(100);
}

Path.prototype.add = function(position, force) {
  // Add a new particle with a position, force, and hue
  this.particles.push(new Particle(position, force, this.hue));
}

// Display plath
Path.prototype.update = function() {  
  for (var i = 0; i < this.particles.length; i++) {
    this.particles[i].update();
  }
}  

// Display plath
Path.prototype.display = function() {
  
  // Loop through backwards
  for (var i = this.particles.length - 1; i >= 0; i--) {
    // If we shold remove it
    if (this.particles[i].lifespan <= 0) {
      this.particles.splice(i, 1);
    // Otherwise, display it
    } else {
      this.particles[i].display(this.particles[i+1]);
    }
  }

}  

// Particles along the path
function Particle(position, force, hue) {
  this.position = createVector(position.x, position.y);
  this.velocity = createVector(force.x, force.y);
  this.drag = 0.95;
  this.lifespan = 255;
}

Particle.prototype.update = function() {
  // Move it
  this.position.add(this.velocity);
  // Slow it down
  this.velocity.mult(this.drag);
  // Fade it out
  this.lifespan--;
}

// Draw particle and connect it with a line
// Draw a line to another
Particle.prototype.display = function(other) {
  stroke(0, this.lifespan);
  fill(0, this.lifespan/2);    
  ellipse(this.position.x,this.position.y, 8, 8);    
  // If we need to draw a line
  if (other) {
    line(this.position.x, this.position.y, other.position.x, other.position.y);
  }
}
<html>
  <head>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.6.0/p5.js"></script>
    <script src="sketch.js"></script>
  </head>
  <body>
  </body>
</html>