Skip to content
Downsample plugin for Flot charts.
JavaScript HTML CSS
Branch: master
Clone or download

Latest commit

Fetching latest commit…
Cannot retrieve the latest commit at this time.


Type Name Latest commit message Commit time
Failed to load latest commit information. Update demo URLs Apr 19, 2020
demo_data.js Initial commit May 14, 2013
example.css Initial commit May 14, 2013
example.html Fix missing Flot library url in example Feb 16, 2019
example.js Initial commit May 14, 2013
jquery.flot.downsample.js Version jump to 1.0 (original version seems pretty stable) Nov 19, 2013

flot-downsample: Downsample plugin for Flot

This plugin for Flot charts downsamples data before rendering the chart. The purpose is to try retain the visual characteristics of the original line using considerably fewer data points. The algorithm (called Largest-Triangle-Three-Buckets or LTTB) used in this plugin is described in a Master's thesis (see in Computer Science by Sveinn Steinarsson at the University of Iceland. The topic of the thesis is how to downsample time series for visual representation and was initially suggested by DataMarket. JavaScript optimization was done with the help of Borgar Þorsteinsson.


Demo can viewed at

Additional demo concerning chart resizing is also available at


series: {
  downsample: {
    threshold: 1000 // 0 disables downsampling for this series.

Known limitations

  • Does not support gaps (null values) in the data array.
  • X-values must be in a strictly increasing order.

Articles related to the algorithm (LTTB)

The algorithm (LTTB) adapted for other programming languages or frameworks

Note: I have not tested all these versions and some might have different or additional features.

(Please let me know if you make your own port of the LTTB algorithm so I can list it here.)


flot-downsample is released under the terms of the MIT License.

You can’t perform that action at this time.