Use this tool to digitise 2D plots and Contours. For regular plots and graphs use graphreader normal mode

1) Select image by Browse or Drag the image file onto the page. JPG, PNG or GIF formats are accepted.
2) Resize the rectangular selector to mark the area to be analysed
3) Place the A-B line over the Colorbar so it covers all the colors
4) Type the corrsponding 'Colorbar values (A->B)'. Type the start and end -values, e.g. '1,10' for automatic intervals, or type all intervals manually e.g.'1,2,4,6,10'
5) Select 'Colorbar Type' whether the colorbar legend has smooth continuous colors or is composed of discrete color steps
6) Press 'Generate 2D plot' and the result is shown in grayscale. The data is also show below as JSON or CSV
For more help and details on finetuning, see the Help page

            Browse or Drag & Drop the Image file




Analysis Area

Chart analysis area

Legend colorbar coordinates

Codes for quick saving and loading of the above settings

Output 2D Array Data

No errors or warnings occured

Process Log


Graphreader is meant to offer a set of simple online tools for extracting values from image based graphs and plots, and export those data into comma seperated values (CSV) or JSON.

Graphs and curves are effective tools for presenting results in reports and publications, however they are also effective means of manupulation since it can be a challenge to grasp and compare the exact values. With graphreader it is time to go deeper into those data and carry out real quantitative analysis.

Obviously, the resulting values will at best be an approximation to the original data set, and you need to do your own data validation, especially when using the machine estimation feature. There may easily be slight offsets and systematic errors, however normally you will get a good idea of the actual data.

Data privacy

Uploaded data will not be used or shared in any way, however since I am not in full control how data is stored and backed up on the hosted cloud service, please dont upload any confidential material.

Contact and Feedback

This tool is developed as a project in web-programming, data science and python.
Feel free to leave your feedback on .
You may check out my Blog on audio field recordings at
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