I created a html file using leaflet to add markers to leaflet map using csv data. For parsing csv data I used papaparse. I did the same thing with python folium too and saved the output to a file called map.html. Both of them are unresponsive on opening on the browser and keep loading for ages. I thought it was because the dataset is huge and tried deleting some values and trying again

<!DOCTYPE html>
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta charset="utf-8">

  <link rel="stylesheet" href="https://unpkg.com/leaflet@1.7.1/dist/leaflet.css"/>
  <script src="https://unpkg.com/leaflet@1.7.1/dist/leaflet.js"></script>
  <script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
  <script src="https://cdn.jsdelivr.net/npm/papaparse@5.3.0/papaparse.min.js"></script>

    body { margin:0; padding:0; }
    #map { position: absolute; top:0; bottom:0; right:0; left:0; }


  <div id="map"></div>


  var map = L.map('map', {
    center: [24.2170111233401, 81.0791015625000], 
    zoom: 9,
    scrollWheelZoom: false,
    tap: false

  var controlLayers = L.control.layers( null, null, {
    position: "topright",
    collapsed: false

  var light = L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png', {
    attribution: '&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a>, &copy; <a href="https://carto.com/attribution">CARTO</a>'
  controlLayers.addBaseLayer(light, 'Carto Light basemap');

  var terrain = L.tileLayer('https://stamen-tiles.a.ssl.fastly.net/terrain/{z}/{x}/{y}.png', {
    attribution: 'Map tiles by <a href="http://stamen.com">Stamen Design</a>, under <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>. Data by <a href="http://openstreetmap.org">OpenStreetMap</a>, under <a href="http://www.openstreetmap.org/copyright">ODbL</a>.'
  controlLayers.addBaseLayer(terrain, 'Stamen Terrain basemap');

  $.get('lat-long.csv', function(csvString) {

    var data = Papa.parse(csvString, {header: true, dynamicTyping: true}).data;
    for (var i in data) {
      var row = data[i];

      var marker = L.marker([row.latitude, row.longitude], {
        opacity: 1


    'Leaflet Js openstreetmap'


This is my python code

import folium
from folium import plugins
import pandas as pd

df = pd.read_csv('lat-long.csv')
m = folium.Map([24.2170111233401, 81.0791015625000], zoom_start=5)

for index, row in df.iterrows():
    folium.Marker([row['latitude'], row['longitude']]).add_to(m)

Edit: My csv file looks like this

  • Any errors in the browser debugger console? What do you se in browser debugger network section? An yes, having your data would help.
    – TomazicM
    Oct 13 at 8:10
  • @TomazicM the page doesnt even load properly,much less let me inspect the source code and see if any bugs have been mentioned. Oct 13 at 8:23
  • Properly loading or not, there must be some trace in the network section of the browser debugger.
    – TomazicM
    Oct 13 at 8:40
  • An alternate approach could be to use QGIS and a plugin named Qgis2web. After you load the CSV file into QGIS you simply use the plugin and it will export an HTML file and other relevant stuff. No coding needed.
    – GreyHippo
    Oct 13 at 14:35
  • How many features are in your CSV file?
    – GreyHippo
    Oct 13 at 14:36

It could be that you are processing too much data. Try to edit your CSV file to only include 100 points and see if that works.

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