Calling All Experienced Contributors: New mappers need your help!

Posted by Xvtn on 31 January 2024 in English. Last updated on 5 February 2024.


New users are requesting a review on their changesets, requests which go unanswered most of the time. We can use OSMCha to easily find them and review them.

“Review Requested”

When just starting out, I’m sure most of us have wondered whether we should tick the box stating “I would like someone to review my edits.” Ever wondered who is reviewing those when requested? Turns out, usually, it’s nobody. (See note below)

In my experience, brand new OSM contributors make mistakes frequently. Also, most new mappers don’t stick with it. Both of these points are OK, but we can correct the mistakes to improve data quality, and hopefully let new mappers feel welcome and like they’re part of the community.

The Solution

Fortunately, there is an excellent tool that makes it easy for experienced mappers to find newbie, review-requested, or suspicious changesets - OSMCha. You can also monitor your local area. It’s really fun!

  1. Go to
  2. Log in with your OSM account.
  3. (Optional) Click on your OSM username dropdown, choose Account Settings. Remove text in “Review Comments Template”. If you don’t, when you verify a changeset as good or bad in OSMCha, it will make an aggressive-sounding comment on your behalf. I prefer to write my own comment on each changeset I review for new mappers.
  4. Click the Filters button and choose filters, see note 1 below.
  5. Click Save in the upper left so you can come back later without having to enter filters again.
  6. Pick a changeset on the left bar, review the changes, and optionally leave a comment. See note 2 below.
  7. In the upper right, verify the changeset as good or bad, and maybe add tags. (You can always change things later.)


Changeset Filters

For reviewing new mappers’ changesets, here are the filters I use:

  • Location - Draw a border around my local area. (I review all in Utah and some in USA west)
  • Reasons for Flagging - “New Mapper”, “Review Requested” (Set to AND!)
  • Review Status - “Not Reviewed”

Changeset Comments

Here are some things I might include in my comments.

  • Mention that rather than nitpicking, I’m reviewing changes specifically because they requested a review.
  • Recognize one or more things done right
  • Welcome them to OSM if they only have a couple changesets
  • Point out potential issues in a friendly way
  • Acknowledge that sometimes there are multiple ways to map things, or that sometimes people will disagree
  • Thanks for your contribution(s)!
  • Sometimes, I say they can ask me if they have any questions.

Changeset Stats

  • In January 2024, there were 37,000 changesets that were tagged “review requested.”
  • 14,000 of them were by new mappers.
  • Only ~500 of them received at least one comment.


Comment from arnalielsewhere on 1 February 2024 at 12:32

this is awesome! Thanks for sharing!

Comment from chris_debian on 1 February 2024 at 14:55

Thanks, Xvtn; I’ll give this a go.


Comment from CoyKoi on 11 February 2024 at 19:41

Thanks for the post. I enjoy reviewing newbie changesets, I find that the challenge for me is staying succinct, while remaining friendly and useful. Once the comment gets a bit longer, I find it difficult to structure due to the lack of formatting options in comments.

Your bulletpoint list of considerations is great.

I would add that you need to know when to hold back: If a changeset has multiple issues, try to focus on one major issue, rather than itemizing every single problem. (And of course letting them know what was done well)

Comment from GeeMaps! on 11 February 2024 at 22:23

Re “If a changeset has multiple issues, try to focus on one major issue, rather than itemizing every single problem”.

An easy option there is too add multiple CCs! 1st is you mention “aaa”, 2nd “bbb” & so on.

As everybody has said though, polite, friendly, & helpful are the main things, rather than “You’ve made a mess”! :-(

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