avoindata.suomi.fi API

Free Finnish government open data API with no key: search national and municipal datasets in Finnish, Swedish and English through the standard CKAN interface. Tested example included.

No API key requiredCORS enabledHTTPSFree tier

Endpoint tested and returned HTTP 200 on 2026-08-21

What is the avoindata.suomi.fi API?

avoindata.suomi.fi is Finland's national open data portal, exposing a free, key-free CKAN API. It provides search and metadata access to datasets from Finnish government agencies, municipalities and public bodies, with titles and descriptions localised in Finnish, Swedish and English.

Finland's portal is operated by the Digital and Population Data Services Agency as part of the wider suomi.fi public services platform. Coverage is strong on statistics, geospatial data from the National Land Survey, transport, environmental monitoring and municipal datasets from Helsinki and other cities.

The multilingual handling is the thing that distinguishes it from other CKAN portals. Finland is officially bilingual, and dataset titles and descriptions frequently arrive as objects keyed by language code — `fi`, `sv`, `en` — rather than plain strings. Code that assumes a string title will break here, and English is not always populated, so implement a language fallback chain rather than assuming a single field.

Quick facts

Base URL: https://avoindata.suomi.fi/data/api/3/action
Authentication: No API key for read operations. Publishing requires an account with the portal.
Rate limit: No published limit. Reasonable paging expected.
Pricing: Free. Most datasets are CC BY 4.0; check per dataset.
CORS: Enabled — callable directly from browser JavaScript
Official docs: Read the docs

How to use the avoindata.suomi.fi API

Every request below was executed against the live API on 2026-08-21, and the response shown is the real body it returned — not an illustration.

1. Search Finnish government datasets

GET https://avoindata.suomi.fi/data/api/3/action/package_search?rows=1

curl

curl 'https://avoindata.suomi.fi/data/api/3/action/package_search?rows=1'

JavaScript (fetch)

const res = await fetch("https://avoindata.suomi.fi/data/api/3/action/package_search?rows=1");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);

Python (requests)

import requests

res = requests.get("https://avoindata.suomi.fi/data/api/3/action/package_search?rows=1", timeout=20)
res.raise_for_status()
print(res.json())

Response — HTTP 200 (truncated)

{
  "help": "https://avoindata.suomi.fi/data/api/3/action/help_show?name=package_search",
  "success": true,
  "result": {
    "count": 2560,
    "facets": {},
    "results": [
      {
        "author": null,
        "author_email": null,
        "collection_type": "Open Data",
        "copyright_notice_translated": {},
        "creator_user_id": "5cc316a0-a178-4bf9-86fd-6047d26ea3d2",
        "date_released": "2026-08-17T00:00:00.000000",
        "deprecated": false,
        "external_urls": [
          "https://www.hsy.fi/ilmanlaatu-ja-ilmasto/ilmastonmuutos/hiilitase/"
        ],
        "geographical_coverage": [
          "espoo",
          "helsinki",
          "kauniainen",
          "vantaa"
        ],
        "highvalue": "false",
        "highvalue_category": [],
        "id": "900807ec-20a8-488f-b982-682f7407f7ed",
        "isopen": false,
        "keywords": {
          "fi": [
            "hiilitase",
            "hiilinielu",
            "maankäyttö"
          ]
        },
        "license_id": "cc-by-4.0",
        "license_title": "Creative Commons Attribution 4.0",
        "license_url": "http://creativecommons.org/licenses/by/4.0/",
        "maintainer": "Helsingin seudun ympäristöpalvelut HSY",
        "maintainer_email": [
          "avoindata@hsy.fi"
        ],
        "maintainer_note_translated": {},
        "maintainer_website": "https://www.hsy.fi/avoindata",
        "metadata_created": "2026-08-17T00:00:00.000000",
        "metadata_modified": "2026-08-17T20:29:17.217751",
        "name": "paakaupunkiseudun-hiilitaseselvitys",
        "notes": "Aine

Parameters

Parameter	Type	Required	Description
`q`	query	Optional	Free-text Solr query. Finnish terms usually match more than English ones, since not every record is translated. `väestö`
`rows`	query	Optional	Datasets per page. Defaults to 20. `1`
`start`	query	Optional	Pagination offset. `0`
`fq`	query	Optional	Filter query, for example by organisation or resource format. `res_format:CSV`
`sort`	query	Optional	Sort order, such as `metadata_modified desc`. `metadata_modified desc`

Response fields

successboolean: Whether the CKAN action succeeded.
result.countinteger: Total datasets matching the query.
results[].titlestring or object: Dataset title. Often an object keyed by `fi`, `sv` and `en` rather than a plain string — handle both shapes.
results[].notesstring or object: Description, with the same multilingual shape as the title.
results[].organizationobject: Publishing agency or municipality.
results[].license_idstring: Dataset licence. Most are CC BY 4.0.
results[].resourcesarray: Downloadable files and API endpoints with formats and URLs.
results[].metadata_modifiedstring: ISO timestamp of the last metadata change, useful for incremental harvesting.

What you can build with the avoindata.suomi.fi API

Find Finnish statistics, geospatial or environmental datasets
Harvest Nordic open data metadata into a shared catalogue
Monitor Finnish municipalities for newly published datasets
Locate direct CSV or GeoJSON download URLs for analysis

Common errors and how to fix them

Title is an object, not a string

Not an error — Finland stores multilingual values.

Fix: Check the type before rendering, and fall back through `en`, `fi`, `sv` so the UI never shows an object.

HTTP 200 with success false

CKAN rejected the parameters.

Fix: Read `error.message` in the response body.

Empty results for English terms

Not every dataset is translated into English.

Fix: Search in Finnish where possible, or use `fq` with organisation filters to browse instead.

avoindata.suomi.fi API — frequently asked questions

Is the Finnish open data API free?

Yes, all read operations are free with no API key. It is run by the Digital and Population Data Services Agency as part of the suomi.fi platform.

Why do Finnish dataset titles come back as objects?

Finland is officially bilingual, so CKAN stores titles and descriptions keyed by language code — `fi`, `sv` and `en`. Code that assumes a plain string will break, and English is not always populated, so implement a fallback chain.

Does this API work the same as other CKAN portals?

Yes, the actions and parameters are standard CKAN, so the same client works against Ireland's, Australia's and other national portals. The multilingual field shapes are the Finland-specific detail to handle.

What data is available from Finland's portal?

Statistics, National Land Survey geospatial data, transport, environmental monitoring, and a substantial body of municipal datasets from Helsinki and other cities. Most is CC BY 4.0 licensed.

Tools that pair with this API

CSV to JSON Converter

Convert CSV to a JSON array of objects online. Header-row detection, comma/semicolon/tab delimiters and pretty-printed output — 100% in your browser.

JSON to CSV Converter

Convert a JSON array of objects to CSV online. Automatic column headers from the union of all keys, delimiter choice and proper quoting — all in-browser.

CSV Viewer & Table

View CSV as a clean HTML table online. Live search filter, row and column counts, delimiter and header options — all processed locally in your browser.

avoindata.suomi.fi is an independent third-party service and is not affiliated with ByteTools or ByteVancer. Details on this page were verified on 2026-08-21; always check the official documentation before relying on this API in production, as terms and limits can change.