Directory of Danish open data sources

This directory contains an open, machine-readable, and verified catalog of essential Danish open data sources, APIs, and portals.

The catalog provides a curated and operational index of Denmark's digital data ecosystem across sectors: cultural heritage, research, meteorology, real-time energy, parliamentary proceedings, legislation, natural language processing, the environment, and spatial data.

Each entry documents the publishing institution, primary domain, portal URL, machine-readable API endpoint (where available), license model, authentication requirements, and supported data formats.

📂 Files in this Catalog

All files feature direct format-pill links:

📊 Dataset Key Figures & Facts

• Registered Sources: 25 verified Danish open data sources.
• Validation Status: 25 out of 25 endpoints actively verified with HTTP 200 OK.
• Domains Covered: 7 core sectors (Culture & History, Environment & Energy, Language & NLP, Society & Demographics, Geodata & Infrastructure, Governance & Law, Municipalities & Research).
• Openness: 100% free access without paywalls. Most sources offer instant open access without API keys, or free self-service registration.
• Catalog License: Dedicated to the public domain under CC0 1.0 Universal.

📋 Data Schema and Columns

The catalog is distributed in two complementary formats:
1. JSON (danske_aabne_datakilder.json): Hierarchical structure with catalog metadata, changelog, and source array.
2. CSV (danske_aabne_datakilder.csv): Flat tabular export encoded in UTF-8 with comma delimiters:

🏛️ Overview of Sources by Domain

1. Culture, Arts & History

• SMK Open (National Gallery of Denmark): Free REST API accessing 250,000+ digitized artworks in the Public Domain (CC0 / PDM).
• National Museum of Denmark Online Collections: Artifacts, historical photographs, and archival records.
• Royal Danish Library (KB Labs): Pre-1880 digitized historical newspapers, Danish literature corpora, and music registers.
• Listed & Preserved Buildings (FBB): Agency for Culture and Palaces spatial service for protected architectural heritage.
• Danish National Archives (Rigsarkivet): Digital records, parish registers, censuses, and historical source documents.
• Project Runeberg: Nordic open library preserving historical Danish literature and reference works (Salmonsens encyclopedia, etc.).

2. Environment, Climate & Energy

• DMI Open Data: Modern keyless OGC REST APIs for weather observations, radar imagery, oceanography, and climate data.
• Energi Data Service (Energinet DataHub): Real-time electricity generation (wind, solar), grid transmissions, CO2 emissions, and spot prices (CC0).
• Danish Environmental Portal (Arealdata): WMS/WFS spatial services for protected nature (§ 3), waterways, soil pollution, and water resources.
• GEUS Jupiter Database: National groundwater and geological borehole database holding 280,000+ drillings and chemical analyses.

3. Language, Linguistics & Reference

• Central Word Register (COR): The Danish Language Council's official register of authorized Danish vocabulary (CC0).
• Sprogteknologi.dk: Agency for Digital Government portal for open Danish language models, text corpora, and speech assets.
• DSL Corpus & Dictionaries: Society for Danish Language and Literature open language resources and corpora.
• Lex.dk: National encyclopedia platform with 230,000+ peer-reviewed articles from Trap Danmark and Den Store Danske.

4. Demographics, Society & Economy

• Statistics Denmark (StatBank API): Thousands of time series covering population, economics, labor, and social conditions (CC BY 4.0).
• National Health Service Organisation Register (SOR): Health Data Authority master registry of all hospitals, departments, and clinics in Denmark.
• Central Business Register (CVR Data): Danish Business Authority company registry accessible via an Elasticsearch REST API.

5. Spatial Data, Transport & Infrastructure

• Dataforsyningen: Agency for Climate Data base maps, Elevation Model (DHMR), cadastral boundaries, and orthophotos (CC BY 4.0).
• Datafordeleren: Central government data distribution hub for fundamental registers (DAR addresses, BBR buildings, cadastre).
• Rejseplanen Labs API: Public transit routing, schedules, and departure boards for trains, buses, and metro across Denmark.
• Danish Road Directorate Open Data: Traffic events, roadworks, sensor stations, and EV charging infrastructure in DATEX II format.

6. Governance, Law & Parliament

• Danish Parliament Open Data (ODA): OData REST API for bills, parliamentary voting records, agendas, committees, and politicians.
• Retsinformation Open Data API: Danish legislation, executive orders, circulars, and legal notices via REST JSON and ELI Atom feeds.

7. Municipalities & Research

• Open Data DK: Inter-municipal CKAN portal hosting 630+ municipal datasets (parking, sensors, local budgets).
• DeiC Dataverse: National FAIR research data archive serving Danish universities and research institutions.

🔄 Validation & Auditing

The catalog is verified on an ongoing basis using an automated test suite. Each execution pings all endpoints, records latency, and synchronizes the flat CSV table with the primary JSON file:

pip install requests

python data/danske_aabne_datakilder/valider_kilder.py

Results are appended to audit_log.jsonl with timestamp, HTTP status code, and latency (ms) for every registered source.

📜 Licensing & Terms

• Catalog License: This catalog index, validation tooling, and documentation are provided under the CC0 1.0 Universal (Public Domain Dedication).
• Individual Datasets: Data accessed through these endpoints remains the property of the respective publishers and is governed by their individual terms (e.g., CC BY 4.0 for Statistics Denmark and Dataforsyningen, or CC0 for Energi Data Service and COR). Consult the licens field in each record for source-specific terms.