What is Plotly.js and Should You Use it in 2025?

Numbers can tell a powerful story, but for many people, just seeing a bunch of numbers in a table does not make for a very compelling one. Instead, you can use data visualization through graphs and charts. Instead of numbers, you can depict data points more visually, allowing the end-user to understand what is going on and make data-driven decisions more easily.

One way to visualize data points in your product or app is to use a Javascript chart library. Plotly.js is a popular Javascript visualization library used by developers worldwide.

But is it the best tool for the job? Let’s find out.

What is Plotly.js?

Plotly.js is an open-source Javascript chart library for creating interactive visualizations on the web. It is based on WebGL and D3.js and it allows developers to build highly customizable visualizations without much complication.

Plotly offers both open-source and enterprise products:

• Dash
• Dash Enterprise
• Chart Studio Cloud
• Chart Studio Enterprise
• Data visualization libraries
• Figure converters

Today, we’ll primarily focus on the visualization libraries.

If you take a look at plotly.com, you’ll see that it supports a decent number of chart types:

• Line charts
• Bar charts
• Scatter plots
• Histogram charts
• Pie charts
• Choropleths
• 3D charts
• Heatmaps
• Treemaps
• SVG and tile maps

Some of the key features of this Javascript library are:

Compatibility: it can easily be integrated into web applications and frameworks such as React and Angular.

Customizability: you can add styling, annotations, and advanced configurations on top of standard templates.

Interactivity: the user can zoom in and out, pan, hover, and select data points within visualizations in the y-axis and x-axis.

All of these features, combined with the fact that it’s open source, make Plotly graphs an attractive option for developers.

Pros and cons of using Plotly.js for data visualization

Out of all the JS charts, Plotly stands out in terms of its versatility. But before you make a choice for your next data science project, consider its pros and cons first.

Pros:

• High interactivity: gives the end-user a wealth of options to interact with data through zooming, panning, and hovering, letting them explore the data on their own terms.
• Versatile chart options: from bar charts to heatmaps, there are many options for different data types and use cases.
• Web-friendly: it’s designed for web applications and supports technologies such as Angular, React, and Vue.
• Customization: you can adjust styles and annotations and create custom interactions.
• Community and documentation: since it’s open source and free, there is a vast community of developers to tap into and ample documentation (e.g. a tutorial on platforms like Github) in case you get stuck.

But there are also some things that are less than ideal if you choose a Plotly chart.

Cons:

• File size: Plotly.js can be sizeable, which hinders performance on mobile devices and slower connections.
• Performance with large databases: Plotly handles smaller file sizes easily, but it could do better with very large data sets. Visualizations can take considerably longer to load, which may require optimization or alternative tools.
• Complexity for simple visualizations: Creating a simple bar chart can be overly complicated in Plotly.
• Licensing for advanced features: Plotly's basic functionalities are free, but the more advanced features and extensions require a paid license.

Is Plotly.js free?

In its basic version, Plotly is completely free to use. However, Plotly Dash Enterprise is not free. This data app platform for Python has custom pricing based on your needs and requirements.

The better alternative to Plotly.js

Using Javascript chart libraries is a decent starting point for visualizing your data, but it has certain limitations. If you’re looking for data visualizations in an embedded setting, you want something that is even more flexible, supports a large number of chart types and is easy to customize.

In other words, you need Luzmo.

With Luzmo, you get a number of benefits compared to Javascript:

• Rapid development: thanks to Luzmo API, your developers don’t need specialized knowledge to connect visualizations to your website or app. Anyone with the basic knowledge of HTML or CSS can create visualizations in Luzmo.
• A huge variety of chart types: Luzmo supports 50+ types of charts, from bar charts to heatmaps, choropleths and histogram charts
• Advanced features: Luzmo supports multi-tenancy, localization, multiple currencies and timezones, as well as interactivity of dashboards
• Seamless integration: thanks to API, SDK and extensive developer documentation, you can embed Luzmo dashboards in any app or website within hours, not weeks or months
• Customization capabilities: you can customize the dashboard with your brand colors, fonts and logos, making it blend into your product seamlessly

So why settle for less? With Luzmo, you get all the benefits of Javascript chart libraries such as Plotly, but none of the downsides.

Don’t take our word for it. Get a free demo of Luzmo to see why it’s better than Plotly.js.