Useful by design.
Open by intention.
ChartsAI is a collection of free visual tools built by SupaMakers. We want making a chart or printing a tracker to feel like a small, satisfying task.
A finished example is a better start.
Every tool starts with something you can use immediately. You can explore the example, replace its data, and download the result. Our examples are original and explicitly fictional; they are demonstrations of the tools, not claims about real people or businesses.
Keep the meaning intact.
A pretty chart is only useful when it represents the values you meant to show. Our import preview lets you select a sheet, choose columns, and specify number formatting. We flag missing or invalid values instead of replacing them with zero. We do not remove outliers, infer business metrics, or normalize mixed units without your involvement.
Dot plots
Each selected observation produces one dot. Identical numeric values stack at the same horizontal position. No automatic binning or rounding is applied to the observations. The frequency table exposes the counts behind the drawing. The mean, median and range use the included observations; the display formats values to a maximum of six decimal places.
This implementation is for frequency dot plots. It supports up to 300 observations. Very close values can be visually crowded; use the frequency table to inspect their exact values. The chart is not a substitute for checking the underlying data.
Radar charts
Axes share a zero-to-maximum scale, and score positions vary linearly along each axis. All series use the same dimension order. Missing, negative and out-of-range values are flagged. Changing axis order changes the shape, so the enclosed area is not presented as an overall score. For more context, see Data to Viz’s discussion of radar charts.
Line graphs
Line graphs connect observations in the supplied row order. Equal spacing treats labels as categories; numeric distance and UTC date spacing preserve actual intervals. Numeric/date positions must be strictly increasing. Missing values, impossible dates and duplicate positions are flagged rather than guessed. Values are not smoothed, forecast, aggregated or normalized. All series share one vertical scale, with zero included by default.
Habit trackers
Monthly layouts use the Gregorian calendar and include leap-year February. Weekly layouts use Monday through Sunday with a blank start-date field. The PDF uses the selected A4 or US Letter dimensions. This is a printable template, not a health assessment or a behavior-change guarantee.
Proven rendering. Open implementation.
The chart makers use Apache ECharts’ built-in scatter, radar and line charts. Our application provides the data validation, presentation settings and examples. The same option builders drive the static previews, interactive editors and exports. Chart PDFs contain a high-resolution image; SVG exports retain vector shapes and text.
Your input stays with you.
Parsing, calculations and file generation happen in your browser. We do not receive your spreadsheet or habit list. There is no account or cloud history; download your data or finished output before closing the page. Read the privacy details.
Made to be used, and learned from.
Charts, trackers and sample datasets are free to use. The implementation is available under the MIT license, so you can inspect the logic and adapt it. Download the source code and read the reuse notes.
The makers
SupaMakers builds practical software and AI systems. ChartsAI is one of our public projects: a small place to make useful things, publish our choices, and improve them through use.
Found a calculation issue, confusing input, or a layout that needs attention? Send feedback to support@chartsai.com. Include a fictional or anonymized example when possible.
Looking for a starting point? Make a dot plot, compare a radar chart, or print a habit tracker.
Contact
For feedback or questions, email support@chartsai.com. For bugs and improvements, open an issue on GitHub using fictional sample data.