When comparing D3.js vs KoolChart, the Slant community recommends D3.js for most people. In the question“What are the best JavaScript charting libraries? ” D3.js is ranked 2nd while KoolChart is ranked 17th. The most important reason people chose D3.js is:
D3.js is a very popular tool with an active community, resulting in plenty of learning resources and fast responses to questions.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Large community
D3.js is a very popular tool with an active community, resulting in plenty of learning resources and fast responses to questions.
Pro Huge number of examples online
Most of the examples provided are by the author, but there's also a great community writing plugins and more examples.
Pro Doesn't require a proprietary framework
D3's emphasis on web standards gives you the full capabilities of modern browsers without tying yourself to a proprietary framework.
Pro Versatile library for manipulating data on the DOM
Pro Very flexible join paradigm
Can be tricky at first, but once learned, data manipulation and binding can easily generate complex visualizations for massive amounts of data.
Pro Great for highly interactive scenes
D3.js offers incredible levels of interactivity.
Pro Backwards compatible
D3.js is intended for modern browsers, so supports IE9 and above (IE8 with an additional library) as well as all the other modern browsers.
Pro Charts look beautiful
The colors and shapes of charts are very beautiful.
Pro Event handling and user interactivity
If you have data that meets certain conditions, you can highlight it or create another chart at that data point. Also, you can use the built-in data editor to simulate the chart while directly modifying the chart data
Pro The most numerous sample charts provided
30 chart types and 400 ready-to-use sample charts are pre-packaged in KoolChart, which is the most numerous provided in a single package. Here are some sample charts available.
https://www.koolchart.com/demo/line_chart
https://www.koolchart.com/demo/histogram_chart
https://www.koolchart.com/demo/target_chart
https://www.koolchart.com/demo/wing_chart
Pro Very easy and intuitive
Pro Lazy data processing
This is a very useful feature when used with the scroll function because of the large amount of data.

Pro Candlestick charts
Pro Various types of charts are available
KoolChart provides a variety of useful charts. It can bring your business data effective visualization.
Cons
Con Steep learning curve
The complexity and flexibility of D3.js results in it being a time-consuming tool to learn for many users.
D3 is incredibly flexible; probably more so than any other JavaScript visualization library at the time of this posting. With that flexibility comes increased complexity. If you just want to create some quick charts you will get results faster with something else.
Con "Selections" are elegant, but somewhat hard to grok
Selections are core to working with D3 beyond the basics. They're powerful and useful, but require new developers to get up to speed (e.g. set aside 30m to read and digest: https://github.com/mbostock/d3/wiki/Selections) and if used in the context of a larger application will result in a portion of the code using different patterns than the rest, requiring a translation layer in between.

Con Not open source - 2 month trial
