Plotly.js vs uPlot
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A JavaScript library for drawing interactive charts in web pages, also the engine behind Plotly in Python and
Open source · MIT
A small, fast JavaScript chart library for time series, lines, areas, OHLC and bars.
The short answer
Choose Plotly.js if you need…
- Web developers who want interactive charts in their own site or app
- Data analysts who already use Python or R Plotly and want to understand the JavaScript side
- Teams building dashboards that need 3D or scientific chart types
- People comfortable with basic HTML and JSON who want charts without much code
Choose uPlot if you need…
- Web developers who need a fast chart for large time series data
- Dashboards that update live with streamed data
- Apps where a small download size matters
- Projects that need zoom and cursor sync across multiple charts
Side-by-side
| Plotly.js | uPlot | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 18.4k | 10.6k |
| Setup difficulty | Beginner | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | JavaScript | JavaScript |
| Last code update | 8 days ago | 7 days ago |
What each one is
Plotly.js
Plotly.js is a JavaScript library that draws interactive data visualizations such as statistical charts, 3D graphs, scientific charts, map charts and financial charts. You describe your data and layout as a JSON-like object, and the library renders the chart in a web page. The same library also powers the Python and R packages named plotly.
uPlot
uPlot is a JavaScript library that draws charts in a web page using the browser's Canvas 2D drawing API. It is built for plotting time series data such as lines, areas, OHLC and bars. The README says it is about 50 KB minified and aims to render large datasets quickly with low memory use.
Best for
Plotly.js
- Web developers who want interactive charts in their own site or app
- Data analysts who already use Python or R Plotly and want to understand the JavaScript side
- Teams building dashboards that need 3D or scientific chart types
- People comfortable with basic HTML and JSON who want charts without much code
uPlot
- Web developers who need a fast chart for large time series data
- Dashboards that update live with streamed data
- Apps where a small download size matters
- Projects that need zoom and cursor sync across multiple charts
Strengths
Plotly.js
- Supports dozens of chart types, including 3D, scientific, map and financial charts
- Can be used with no build step by loading it from a CDN, or installed through npm
- Actively maintained by Plotly, with an MIT license
uPlot
- The README reports strong benchmark results against other chart libraries, with a small bundle size
- Supports time zones (IANA names) and daylight saving time, plus features like missing data handling and high/low bands
- Has a plugin and hooks API for extending behavior
Not ideal for
Plotly.js
- Users who only need a simple static chart image; a lighter charting library may be enough
- Projects with strict bundle size limits unless they choose a custom or partial bundle, since the full build is large
- Anyone needing WebGL 2 features, since the README only mentions a WebGL 1 workaround for multiple graphs
uPlot
- People who want a ready-made chart with no coding, since the README focuses on the API and docs are described as a work in progress
- Projects needing built-in drag panning, since the README says it is not included and must be added via plugins
- Very large live views above about 100k points, which the README says may struggle
- Projects needing 3D or WebGL-style rendering, since the README points to other libraries for that
Trade-offs
Plotly.js
- The full bundle is large, so you may need to build a custom bundle to keep pages light
- Advanced setup such as custom builds or bundling requires reading additional guides
- Some features like MathJax rendering need separate loading and extra configuration
uPlot
- The README says the docs are a work in progress, so some APIs need to be learned from the type definitions and demos
- Does not include data parsing, aggregation or statistics, and has no animations or built-in panning
- Axis tick labels have no collision avoidance, so spacing may need manual tuning
Getting started
Plotly.js
Install the ready-to-use distributed bundle
npm i --save plotly.js-dist-minuPlot
Clone the repository
git clone https://github.com/leeoniya/uPlotFrequently asked questions
What is the difference between Plotly.js and uPlot?
Plotly.js: A JavaScript library for drawing interactive charts in web pages, also the engine behind Plotly in Python and . uPlot: A small, fast JavaScript chart library for time series, lines, areas, OHLC and bars. Plotly.js suits web developers who want interactive charts in their own site or app, while uPlot suits web developers who need a fast chart for large time series data.
Are Plotly.js and uPlot free?
Plotly.js: Free and open source. uPlot: Free and open source.
Which is easier to set up, Plotly.js or uPlot?
Plotly.js is easier to get started with (rated beginner); uPlot is rated intermediate and usually needs more setup.
Is Plotly.js or uPlot more popular?
Plotly.js has more GitHub stars (18.4k) than uPlot (10.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Plotly.js and uPlot?
Other options people compare them with include Chart.js, plotly.py, visx, deck.gl, Recharts.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.