We can build a better map

DistrictBuilder puts the power of drawing electoral maps in the hands of the people. Redistricting can be a transparent process that represents communities fairly and prevents gerrymandering.

DistrictBuilder is a free and open source redistricting tool.

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Accurate down to the block

DistrictBuilder’s software gives you access to the same block-level data used in legal redistricting plans — for free. Come to the table with electoral maps that better reflect local communities and lead to fair representation.

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Uncover inequalities

Evaluate population demographics and visualize the effects of gerrymandering.

Build beautiful maps

Rapidly draw visually engaging and informative maps in our modern interface.

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Engage your audience

Easily export your custom map and share in an article, on social media, or anywhere online.

We’re making DistrictBuilder the most useful redistricting tool it can be. View our product roadmap to find out what exciting features are coming soon.

What the redistricting community is saying

Over 6,000 people, ranging in age from 13 through 70, used DistrictBuilder to draw their own congressional districts for the commonwealth of Pennsylvania. Our mappers loved the experience of using DistrictBuilder and the visualizations it creates.

Justin Villere

Managing Director at Draw the Lines PA

I can't wait to see this tool become more fleshed out, it already has such great potential and I was having a LOT of fun with the tiny block groups. Keep up the great work!

@labor_law_dad

Fight for fair and transparent redistricting. DistrictBuilder empowers you to draw a better map.

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Redistricting resources and information

Explore questions of proportionality, competitiveness, contiguity, and more, as new legal decisions, public oversight, and technology change the criteria for drawing electoral districts.

Congressional District Population and What It Might Mean for Redistricting

We calculated which congressional districts have become over or underpopulated since they were last drawn.
Getting Started with DistrictBuilder

Not sure where to begin? DistrictBuilder’s wiki has all the information you need to build your first map.
The Public Mapping Project: How Public Participation Can Revolutionalize Redistricting

Want to learn more about Public Mapping? The Public Mapping Project book shares lessons learned, the tech, and how to DIY redistricting.