What GRAVITYSTORM LIMITED does

Gravitystorm Limited, trading as Thunderforest, is a UK-based digital cartography company founded in 2010 by Andy Allan and commercially launched in 2011. The firm builds and operates a global mapping-as-a-service platform that delivers curated, activity-specific map styles (including OpenCycleMap, Transport, Outdoors, Landscape, Atlas, and several specialty styles) on top of OpenStreetMap data, exposing them through four APIs: Map Tiles API (server-rendered raster), Vector Styles API (MapLibre-compatible client-side rendering), Vector Sources API (raw MVT vector tiles), and Static Maps API (fixed map images).

The technical stack is anchored on OpenStreetMap, loaded via the sponsored osm2pgsql tool into PostGIS databases, with raster rendering handled by the sponsored Mapnik engine and proprietary cartographic rules that curate OSM features for specific activities (cycling, hiking, public transit, skiing, etc.). Continuous ingestion means OSM edits surface in Thunderforest maps within hours. The firm also offers a bespoke Custom Cartography service for customers requiring branded or use-case-specific styles.

Commercially, Thunderforest runs a product-led, self-serve B2B model: a free tier with no payment card required, paid plans starting at $125/month with usage-based request pricing, multi-currency billing (EUR, USD, GBP) introduced in January 2026, and Small Business and above tiers required for bulk download/redistribution. Customers include NATS (UK air traffic control), the Federation of Snowmobile Clubs of Quebec, Panintelligence, Komoot, GaiaGPS, and Pedometer++. The company is bootstrapped, profitable, and operates as a small remote-first team.

Name

GRAVITYSTORM LIMITED

Legal name

Gravitystorm Limited

Website

https://thunderforest.com

Company type

Private

Founded year

2010

Operating status

Operating

Short description

Gravitystorm Limited (trading as Thunderforest) is a UK-based, bootstrapped digital cartography company that provides activity-specific OpenStreetMap-based map APIs (raster, vector, static) and custom cartography services to developers and businesses integrating maps into web and mobile applications globally.

Ownership category

akta.pro rank

Headquarters

HQ city

New Malden

HQ country

United Kingdom

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Technology or R&D, Infrastructure, Personnel, Others

Revenue model

1. Map API Requests: Request-based pricing model where customers pay per API request made to map services. Multiple pricing tiers with different request quotas. Monthly billing on the same day as account upgrade. Supports EUR, USD, and GBP billing currencies.
2. Custom Cartography Service: Bespoke map style creation service from branding and custom icons to highlighting or removing specific features. Over 15 years of mapping experience. Additional paid service beyond standard API pricing.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels6 records

Core offering

Thunderforest provides map APIs and curated cartographic styles built on OpenStreetMap data for developers and businesses to embed into web and mobile applications. Its core products include the Map Tiles API, Vector Styles API, Vector Sources API, and Static Maps API, served via API keys without proprietary SDKs. A custom cartography service offers bespoke map styling for enterprise and niche use cases.

Product overview

Thunderforest is a global provider of activity-focused map APIs and tile services built on OpenStreetMap data. The core offering consists of four APIs: Map Tiles API for server-side rendered raster tiles, Vector Styles API for client-side rendered interactive maps, Vector Sources API for raw vector tile data, and Static Maps API for fixed map images. These APIs serve multiple map styles including OpenCycleMap (cycling), Transport and Transport Dark (public transit), Outdoors (hiking/skiing), Landscape (natural terrain), Atlas (minimal navigation base), Spinal Map (heavy metal theme), Pioneer (historical railroad), and Neighbourhood (local areas). A Custom Cartography add-on service enables bespoke map styling. All maps are available globally via API integration with mapping libraries including MapLibre, Leaflet, OpenLayers, and flutter_map.

Differentiator

Problem solved

Functional benefit

Products and services

• Map Tiles API Server-side rendered raster tile service providing pre-made map images in standard Web Mercator tile format for easy integration with mapping libraries like Leaflet, OpenLayers, and MapLibre. Sold via API key access.
• Vector Styles API Client-side rendering API providing MapLibre Style Specification JSON endpoints for interactive maps with smooth panning, zooming, rotation, and tilt capabilities. Sold via API key access.
• Vector Sources API Raw vector tile data access in MVT format for on-device rendering, enabling custom map styling with offline capability and smaller data transfer. Sold via API key access.
• Static Maps API API for generating fixed-position map images with custom dimensions and zoom level, ideal for situations where interactive tiles are not needed. Sold via API key access.
• Custom Cartography Bespoke map styling service where Thunderforest's cartographers create custom map styles tailored to specific branding, features, or use case requirements, leveraging over 15 years of mapping experience.
• OpenCycleMap Award-winning global cycling map style showing bike routes, paths, surface information, and cycling-specific infrastructure including bike parking and water stops. Delivered via Thunderforest's APIs.
• Transport Specialist map style showing public transportation including railways, buses, trams, chairlifts, funiculars, cable cars, ferries, and airports worldwide. Delivered via Thunderforest's APIs.
• Transport Dark Dark variant of the Transport map optimized for dark mode interfaces, with carefully selected colors rather than simple color inversion. Delivered via Thunderforest's APIs.
• Outdoors Map tailored for outdoor enthusiasts showing hiking routes, ski runs, topographical features, trail difficulty grading (SAC scale), chairlifts, and natural features. Delivered via Thunderforest's APIs.
• Landscape Global map style focused on natural landscape features including cliffs, scree, forests, and terrain, using traditional cartographical patterns for visual distinction. Delivered via Thunderforest's APIs.
• Atlas Clean, minimal map style for navigation and local context with soft color palette, suitable for overlaying custom data and ideal as a base map for customization. Delivered via Thunderforest's APIs.
• Neighbourhood General-purpose map style for local areas with condensed street names, uncluttered background, and clear labels standing out for place finding. Delivered via Thunderforest's APIs.
• Pioneer Historical railroad map style evoking late-19th/early-20th century American West with Western fonts, verdigris buildings, and limited color palette. Delivered via Thunderforest's APIs.
• Spinal Map Tongue-in-cheek heavy metal themed map style featuring metal umlauts and re-interpreted place names, demonstrating custom vector tile styling possibilities. Delivered via Thunderforest's APIs.

Quantifiable outcome

• Maps show OpenStreetMap updates within hours of mappers adding them
• +3 more outcomes

Named customers8 records

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Integration14 records

Feature5 records

Partnerships

Four partnerships are on record, tiered core and minor.

• osm2pgsqlcoreTechnology or Integration · 1 January 2020Thunderforest sponsors osm2pgsql, the software used to load raw OpenStreetMap data into their PostGIS databases and process continuous updates. Provides both financial sponsorship and development contributions. Founder Andy Allan worked with lead developer Jochen Topf on the flex backend concept in 2019 and on speeding up diff update processing in 2022.
• MapnikcoreTechnology or Integration · 1 January 2019Thunderforest sponsors Mapnik, the server-side rendering engine used for their raster tiles. Helps ensure the project remains well-maintained and contributes to the frequency of Mapnik releases.
• OpenStreetMapcoreTechnology or IntegrationThunderforest uses OpenStreetMap for almost all map data. Company founder Andy Allan is a long-time volunteer mapper (since 2006) and is one of two maintainers of the OpenStreetMap.org website codebase. Company contributes to improving developer experience for new OSM contributors.
• Jochen TopfminorStrategic or Co-development PartnerLead developer of osm2pgsql who worked with Thunderforest on the flex backend concept and on speeding up diff update processing. Collaborated on geometry processing improvements for vector tiles.

Scale indicators8 records

Recent moves6 records

Expansion highlights5 records

Regional players

• Komoot: Komoot is both a Thunderforest customer (per logo) and a route planning platform with its own map style. It represents the kind of activity-specific vertical competitor/partner in cycling and outdoors where Thunderforest's styles are differentiated.
• Gaia GPS: Gaia GPS is an outdoor navigation app that uses Thunderforest maps (per customer logos) and competes in the hiking/outdoor activity map segment. It illustrates the overlap between map API providers and activity-specific app publishers.

Broad incumbents

• Google Maps Platform: Google Maps Platform offers Maps, Routes, and Places APIs for developers and enterprises. It is the default competitor for any developer evaluating Thunderforest for general-purpose web and mobile map integration, with significantly broader feature coverage.
• HERE Technologies: HERE provides commercial map data, tile services, and location APIs used by enterprises across automotive, logistics, and consumer apps. It competes with Thunderforest at the high end of transit and logistics mapping where NATS-class customers operate.
• CARTO: CARTO is a location intelligence and spatial analytics platform offering map visualization APIs and data services. It overlaps with Thunderforest's Atlas-style BI visualization use case (e.g., Panintelligence customer) but targets larger enterprise analytics workloads.

Direct peers

• MapTiler: MapTiler provides self-host and cloud-hosted map tile services plus vector tile generation tooling, sourced from OpenStreetMap. It overlaps with Thunderforest on tile delivery APIs and vector tile infrastructure, competing for the same developer integration use cases.
• Stadia Maps: Stadia Maps offers hosted map tile APIs (raster and vector) including outdoor, cycling, and transit styles built on OpenStreetMap data. It targets the same developer and SMB customer base as Thunderforest with a similar self-serve, API-first model and overlapping activity-specific style library.
• Mapbox: Mapbox is a leading commercial map platform providing tile, static, and vector map APIs built on open and proprietary data. It directly competes with Thunderforest across developer-facing map APIs, with a much larger enterprise footprint and broader style ecosystem.

Emerging players

• OpenStreetMap Foundation (tile servers): The OpenStreetMap project itself operates a public tile server offering basic map rendering. It overlaps with Thunderforest's free-tier utility and is the upstream data and rendering reference for many of Thunderforest's styles.

Others

• Fathom Analytics: Fathom Analytics is a privacy-focused analytics tool that Thunderforest uses on its own site. It is adjacent to Thunderforest's business as a fellow privacy-first, independent SaaS serving developer/SMB customers.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/in/andy-allan-779635a

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about GRAVITYSTORM LIMITED