Input your CSV flow file for analysis:
Result for your analysis:

Polygons To Points

This tool will help you convert your polygon data in geoJSON or topoJSON to CSV file of polygon centroids.

Please input your JSON below:

Normalize Flows

Flow normalization helps remove the effect of total flow or population size by calculating the difference between the actual flow and the expected volume of flow for each pair of locations (nodes). We use an adjusted flow volume formula to calculate the expected number of flows between locations.

For more details in modularity function please refer to Guo (2009).

normalize flows

1. Please choose your flow file that contains three columns: origin, destination, and volume. Then click on Submit button.

2. Your flow file will be processed and returned back to you to download. The output file will include origin, destination, modularity, rawvolume and expectation columns. modularity column is the difference between observed flow (rawvolume) and expected flow (expectation) calculated based on the give formula.

3. Modularity values could be negative or positive. Negative values mean there are less observed flows, whereas positive values mean there are more observed flows than expected from an origin to a destination.

Test Server Connection (beta)

This is a testing tool to connect to the backend Java code, which will provide more complicated analysis tools for pre-processing your data before visualization.

Only for testing use! please input your file below:

Testing result:

Video Tutorial

Tutorial Data

Example data sets are available to download and visualize with FlowMapper in the following link:

Contact Email


Please contact us for any help using FlowMapper. Here are some example feedback:

Tell us about any bugs or problems you experienced with the interface and interactions.

Suggest new additions to FlowMapper. For example, if you would like us to enable any map projection that is not available, we are happy to include your suggested projection.

We are happy to hear any feedback and looking forward to improving your experience with FlowMapper.

Tutorial Data:


About FlowMapper

Version: 1.0.6

Developer: Geng Tian

Supervisor: Caglar Koylu

Citation: Please cite the reference below if you use FlowMapper.

Koylu, C., Tian, G., & Windsor, M. (2022). A web-based framework for designing origin-destination flow maps. Journal of Maps. DOI:10.1080/17445647.2021.1996479.



Error: Nodes and flows do NOT match!

Please make sure the origin and destination IDs used in flow csv file exist in the node file. Please upload your files and select the matching ID columns.

Region Join Results

Number of features: 

Number of joint features: 

Number of disjoint features: