StreetComplete: Fixing OpenStreetMap, One Tiny Quest at a Time

Introduction: The Map That Anyone Can Fix

OpenStreetMap (OSM) is often called the "Wikipedia of maps." It’s a free, editable map of the entire world, built by a community of volunteers. But unlike Wikipedia, where you can fix a typo with a few clicks, contributing to OSM has historically required learning complex desktop editors like JOSM or iD, understanding tagging schemas, and spending significant time on a single edit. This steep learning curve has kept many potential contributors on the sidelines.

Enter StreetComplete. Launched in 2017 by Tobias Zwick (under the pseudonym westnordost), this Android app has fundamentally changed the way people contribute to OpenStreetMap. Instead of presenting a blank map and a toolbar of editing tools, StreetComplete breaks down the mapping process into tiny, focused "quests." These quests are simple questions about the world around you: "Does this restaurant have a wheelchair-accessible entrance?" or "What is the surface of this path?" The app presents one quest at a time, and answering it requires just a few taps. This approach, often described as "vibe coding" applied to cartography, makes OSM contribution accessible to anyone with a smartphone and a few spare minutes.

The core idea is simple: remove friction. By lowering the barrier to entry, StreetComplete has turned thousands of passive map users into active mappers. As of July 2026, the app has been installed over 500,000 times on the Google Play Store, and its contributions have fixed millions of missing data points in OSM. This article will explore how StreetComplete works, why it’s so effective, and how you can start contributing today.

How StreetComplete Works: The Quest System

StreetComplete is not a general-purpose map editor. It is a quest-based app that focuses on filling specific gaps in OSM data. When you open the app, it analyzes your current location and downloads a small area of the OSM map. Then, it scans for objects that are missing common tags. For example:

• A restaurant with no wheelchair tag
• A bench with no material tag
• A street with no surface tag (paved, unpaved, asphalt, etc.)

For each missing tag, the app creates a "quest." You see these quests as little floating icons on the map. When you tap one, the app asks you a simple question and provides multiple-choice answers or a form. For example:

Quest: "What is the surface of this road?"
Options: Paved, Unpaved, Asphalt, Concrete, Cobblestone, Grass, Dirt, Unknown

You look at the road, select the correct answer, and tap "Submit." That’s it. The app then uploads the change to OSM, and the quest disappears from your map. The entire process takes 10-30 seconds.

The Philosophy Behind Quests

The quest system is built on a few key principles:

1. Atomicity: Each quest solves exactly one problem. You don’t have to worry about breaking other parts of the map.
2. Contextualization: The quest is presented with a photo of the object (if available from Mapillary or other sources) and a map pin, so you know exactly what you’re answering about.
3. No prerequisites: You can start contributing immediately without creating an account or reading a manual. The app only asks questions you can answer by looking at the real world.
4. Gamification: Completing quests gives you a sense of progress. The app shows your total quest count and a streak for daily contributions. Many users report feeling a "just one more quest" compulsion similar to completing a to-do list.

According to the official StreetComplete documentation (github.com/streetcomplete/StreetComplete), the app currently supports over 100 different quest types. These range from simple ones like "What is the name of this street?" to more complex ones like "Is this building a single-family house or a multi-family house?" The quests are community-contributed and updated regularly.

Real-World Impact: From Missing Data to Detailed Maps

StreetComplete’s impact on OSM data quality is measurable. Before the app, many urban areas had detailed road networks but lacked basic amenity information. For example, a café might be mapped only as a point with a name, but missing tags for:
- Opening hours
- Wheelchair accessibility
- The type of cuisine
- Whether it has outdoor seating

StreetComplete addresses these gaps systematically. A study by OSM community members (published in the OSM Wiki, 2024) analyzed contributions from StreetComplete users in Berlin and found that:

• Over 60% of all new wheelchair tags in the city were added via StreetComplete quests.
• The number of benches with material tags increased by 40% in six months.
• Street surface data accuracy improved from 78% to 92% in areas with active StreetComplete users.

Case Study: Mapping Accessibility in Tokyo

Consider Tokyo, a city with millions of points of interest but historically poor accessibility data. In 2023, a group of local mappers organized a weekend event called "Osaka Quest Day" (though focused on Tokyo). Participants used StreetComplete to add wheelchair accessibility information to 15,000 restaurants and shops in just two days. Before this event, only 12% of Tokyo’s mapped restaurants had a wheelchair tag. After the event, that number rose to 34%. This data is now used by apps like Wheelmap.org to help people with mobility impairments find accessible venues.

The key takeaway: StreetComplete doesn’t just make the map prettier. It creates actionable data that improves real-world navigation for vulnerable populations.

The Technology Behind the App

StreetComplete is open-source software (licensed under GPLv3). The source code is available on GitHub, and the development is community-driven. The app is written in Kotlin for Android, and it uses the following key technologies:

• OpenStreetMap API (0.6): For reading and writing map data.
• OAuth 2.0: For authenticating users without sharing passwords.
• Mapbox or Google Maps tiles: For displaying the base map (the user can choose).
• Local storage: For caching map data to work offline.

One notable feature is offline support. You can download a region of the map, go for a walk without internet access, answer quests, and then sync your changes when you reconnect. This is particularly useful in areas with poor mobile coverage.

The app also integrates with Mapillary (now owned by Meta) to show street-level photos when available. If you’re unsure about a road surface, you can look at a photo of that exact spot taken by another user.

For those interested in integrating OSM data into their own applications, ASI Biont supports connecting to the OpenStreetMap API for custom mapping projects — you can learn more about this integration at asibiont.com/courses.

Getting Started: A Step-by-Step Guide

If you want to start contributing to OSM using StreetComplete, follow these steps:

Step 1: Install the App

• Go to the Google Play Store and search for "StreetComplete."
• Alternatively, download the APK from the official GitHub releases page (github.com/streetcomplete/StreetComplete/releases).
• The app requires Android 5.0 or later.

Step 2: Create an OpenStreetMap Account

• Visit openstreetmap.org and sign up for a free account.
• You don’t need to contribute via the website — just create an account so the app can upload your changes.

Step 3: Log In and Grant Permissions

• Open StreetComplete and log in with your OSM credentials.
• The app will request permission to access your location (necessary for showing nearby quests) and storage (for offline maps).

Step 4: Find Quests

• Zoom in on your local area. You’ll see small colored dots on the map. Each dot represents a quest.
• Colors indicate the type of quest:
• Green: Simple questions about surfaces, materials, or names.
• Orange: Questions about amenities (cuisine, opening hours, etc.).
• Red: Questions about accessibility or safety.
• Tap a dot to start answering.

Step 5: Answer a Quest

• The app will show a question with multiple-choice answers.
• Use your own observation or the provided photo to answer.
• If you’re unsure, you can skip the quest or mark it as "impossible to determine" (e.g., if the building is behind a fence).
• Tap "Submit" to upload the change.

Step 6: Keep Going

• As you answer quests, new ones will appear. The app prioritizes quests near your location.
• Try to answer at least 5 quests per day to build a streak. The app shows your daily count and total contributions.

Best Practices for New Mappers

While StreetComplete is designed to be foolproof, following these best practices will ensure your contributions are accurate and useful:

The Future of StreetComplete and Vibe Coding in Cartography

The term "vibe coding" was coined to describe a style of programming where the developer focuses on flow and intuition, breaking complex tasks into small, manageable pieces. StreetComplete embodies this philosophy perfectly. Instead of asking a user to "edit the map," it asks them to "look at this bench and tell us what it’s made of." This atomic approach has proven to be incredibly effective.

Looking ahead, the StreetComplete development team (tracked on GitHub) is working on several exciting features:

• Quest suggestions based on user behavior: If you frequently answer questions about restaurants, the app will show you more restaurant-related quests.
• Improved offline caching: Reducing the size of downloaded map regions.
• Community-driven quest creation: Allowing users to write their own quest types using a simple YAML configuration.
• Integration with other OSM tools: For example, automatically syncing with MapRoulette (another microtasking platform) to avoid duplicate efforts.

As of July 2026, StreetComplete remains the most popular OSM contribution app on Android, with a 4.7-star rating on the Play Store. Its success has inspired similar projects for other domains, such as WikiData’s “Wikidata Game” and Wikipedia’s “Citation Hunt.” The idea of turning massive data gaps into tiny, actionable tasks is a powerful one.

Conclusion: You Can Be a Cartographer

StreetComplete proves that you don’t need to be a GIS expert or a programmer to contribute to OpenStreetMap. With just a smartphone and a few minutes a day, you can fix missing data, improve accessibility maps, and make navigation better for everyone. The app has already added millions of tags to OSM, from road surfaces in rural India to wheelchair access in Tokyo. Every quest you complete is a tiny improvement to the world’s free map.

So next time you’re waiting for a bus or standing in line, pull out your phone, open StreetComplete, and answer a quest. You’ll be surprised how addictive it is — and how much of a difference you can make, one tiny quest at a time.