How to Organize a Mapathon


6 min read

Today I gave a lightning talk at State of the Map about how to organize a mapathon. A mapathon, also known as a mapping party, is when a bunch of people get together to edit OpenStreetMap, the editable map of the world. Here’s a guide for organizing a mapathon, based on my experience organizing mapathons in Bogota, Colombia, and Madison, Wisconsin, along with great advice from people who have organized OpenStreetMap mapathons all over the world (thank you, you lovely people!).

First things first: there is no one right way to run a mapathon. I will outline things to consider, but you don’t need to do all of these. Do what works for you, and lean on the wonderful OSM community for support when you have questions.


Find a co-organizer (or two)

A lot can go into organizing a mapathon, including the preparation beforehand and the actual event. It’s helpful to have someone to split up the duties with and who can help attendees on the day of the event.

Determine your priority

Are you organizing a mapathon to add a lot of data to the map, or are you trying to introduce new people to this awesome project? These things aren’t mutually exclusive, but it’s a good idea to keep your main goal in mind as you are planning and running the mapathon.

Find a location

Common places to hold mapathons include local schools, universities, businesses, libraries, restaurants, cafes, or parks. You’ll want to check on the internet connection at the location to try to avoid connectivity issues. Some mapathons have had issues when lots of people try to upload or download data from OpenStreetMap, so you can also check if different computers can connect through different IP addresses.

You might be able to find a local business or organization to sponsor the event to provide food, drinks, and supplies.

Decide on the format

Do you want to do surveying of a local area? Or will you be doing “armchair mapping,” contributing data to the map using aerial imagery or other existing data? If you are going to do outdoors surveying, I recommend meeting at a central indoors location to introduce everyone to OpenStreetMap, splitting up into groups to go off and map nearby, then coming back together at the end to add the collected data to the map. Think ahead of time of possible routes that people can take or certain things that people can map, like addresses, mailboxes, or restaurants. During the event, people are free to map whatever they want, but it’s good to have some ideas ready.

Pick your tools

There are tons of great tools out there to help you contribute to OpenStreetMap. You might want to stick with just one or two to teach at the mapathon so people don’t get overwhelmed by too many options. Or you can provide information about all of them and let people decide what works for them.

Pick an editor

JOSM and iD are the main OpenStreetMap editors, with JOSM being the primary desktop application and iD as the main web-based editor. If you are expecting a bunch of new mappers, you should focus on iD, which has a simpler interface and doesn’t require a download. If you are an expert JOSM user, make sure to familiarize yourself with iD ahead of time so that you can help answer questions that come up. If you are planning to teach JOSM, make sure it is downloaded on available computers or advise people to download it on their own laptops ahead of time.



Reach out to other local organizations to see if they want to work together and help with outreach. This can include a local OSM Meetup group, Maptime chapter, school or university, or the general open-source community. Leverage other organizations’ email lists and social media presence. You can also organize a mapathon in coordination with a nationwide U.S. mapathon to get extra coverage.

Get out the word

Twitter is great, but there are a bunch of other ways to get out the word, too. You can put up flyers around the neighborhood, send out messages to local neighborhood or city lists, or post on Nextdoor.

Asking for RSVPs

It’s a good idea to ask people to RSVP for the event on Meetup, Eventbrite, or Facebook. People can still show up at the door, but it will help with planning if you have an idea whether you’ll have 5 or 55 people.

The day of

Intro to OSM and the tools

Give a brief introduction to OSM. Some people prefer to do this as a 10–30 minute presentation at the beginning of the event, while others prefer giving 3–5 minute presentations throughout the event on different facets of OSM. You can talk about what OpenStreetMap is, different ways to contribute to the project, give examples of ways that it is used, and why open data is important.

Be sure to introduce the tool(s) that you’re going to use during the mapathon. You can mention additional tools that people can use, but focus on just one or two.

Welcome newbies

Hopefully you’ll have people at your event who have never even heard of OpenStreetMap. That’s great! If a new mapper has a positive experience at a mapathon, that will make them more likely to support it in some way. There are lots of ways to do this:

  • Emphasize that you and other experienced mappers are available to help with any questions.
  • Match up experienced mappers with new mappers so that they have a dedicated person who they can go to with questions.
  • Print “Get Started” guides with basic information about OSM and how to edit.
  • Make sure people know that they don’t need to stay for the whole event.
  • Point to additional resources that people can turn to after the event is over.

Get mapping

Go out and survey or start making edits. If you are doing outdoors mapping, make sure someone stays behind at the meeting location in case people show up late or one of the participants has mobility issues.

Most importantly: have fun

Be enthusiastic and have a great time. You are the best ambassador for OpenStreetMap and getting people excited about contributing in whatever way they can.

If you were able to get a sponsor, you can do something social after you’re done with the serious stuff.


If you need more help, here are a few additional resources:

Card photo by Harry Wood

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