A summary from the data
Highest, lowest, first, last, totals, changes and shares, computed from the numbers. Nothing in it is a guess.
Preview
Charts everyone can read
OSCharts turns a table of data into a chart that works for everyone: a summary written from the data, the data table, keyboard and screen reader exploration, sound, and patterns that survive print and high contrast. It reads on a phone, at 400% zoom and on paper, and with JavaScript off.
Free and open source under the Apache License 2.0: use it in anything, including paid products.
Try one
This chart is live. Press Tab until it is selected, then use the arrow keys; a screen reader speaks each value. Or hover, open the data table, turn on patterns, or play it as sound.
Column chart of Public safety, Roads and bridges and Parks by Fiscal year, from 2022 to 2026. Public safety went from $4.1M in 2022 to $5.6M in 2026, a change of +$1.5M (+36.6%). Roads and bridges went from $2.3M in 2022 to $3.1M in 2026, a change of +$800K (+34.8%). Its highest is $3.1M (2026) and its lowest $2.2M (2024). Parks went from $800K in 2022 to $1M in 2026, a change of +$200K (+25%).
- Public safety
- Roads and bridges
- Parks
| Fiscal year | Public safety | Roads and bridges | Parks |
|---|---|---|---|
| 2022 | $4.1M | $2.3M | $800K |
| 2023 | $4.4M | $2.5M | $850K |
| 2024 | $4.8M | $2.2M | $900K |
| 2025 | $5.2M | $2.9M | $950K |
| 2026 | $5.6M | $3.1M | $1M |
Source: Halcyon County sample data (fictional, for the demo)
What every chart has
The data table
Every value, with proper headers, one button away. It always prints.
Keyboard and screen readers
The arrow keys walk the values, and each one is spoken with its position: “Roads, 2024: $2.2M. 3 of 5.”
Not color alone
Every series has its own shape or texture, on from the start, and every color is at least 3:1 against the background in light and dark themes.
Any screen, and paper
Redrawn at the real width, so text never shrinks. Print gets black text, textures and the table.
Safe on strict sites
No dependencies, no inline styles or scripts, rendered on your server or in your browser.
The source
The source code lives in OSCivic/OSCharts on git.oscivic.com, OSCivic's own code host. How to use it is in the repository's README.