Encyclopedia of Life API

Free Encyclopedia of Life API with no key: species pages aggregating names, classifications, traits and media from hundreds of contributing databases and museums.

No API key requiredCORS enabledHTTPSFree tier

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

What is the Encyclopedia of Life API?

The Encyclopedia of Life API is a free, key-free service returning species pages that aggregate content from hundreds of contributing sources. A page request returns the scientific name, every contributing taxonomic concept with its source, and optionally text descriptions, media and trait data.

EOL set out to give every known species a web page, and its API is the machine-readable version of that ambition. What comes back is explicitly an aggregation: the `taxonConcepts` array lists each source that has a record for the organism — a national species list, a museum photo collection, a regional checklist — with that source's own identifier for it. For cross-referencing across biodiversity databases, that mapping is the most valuable thing here.

Set expectations about content depth. Well-studied organisms have rich pages with descriptions, images and traits; obscure ones have little more than a name and a couple of source records. The `details=true` flag pulls in text objects, and separate parameters control images, videos and maps, each of which makes the response substantially larger. EOL's TraitBank is the other reason to use it — structured, sourced measurements such as body mass or habitat, which is unusual among biodiversity APIs and accessible through the same page endpoint.

Quick facts

Base URL: https://eol.org/api
Authentication: No API key required for the public page endpoints; an optional free account key raises limits. Content licences vary by contributor and are stated per media object, so check before reusing images.
Rate limit: Unauthenticated use is throttled per IP. A free API key, available with an EOL account, raises the allowance.
Pricing: Free. EOL is a non-profit project; individual content items carry their own Creative Commons or other licences.
CORS: Enabled — callable directly from browser JavaScript
Official docs: Read the docs

How to use the Encyclopedia of Life 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. Fetch the species page for the western honey bee

GET https://eol.org/api/pages/1.0/1045608.json?details=true

curl

curl 'https://eol.org/api/pages/1.0/1045608.json?details=true'

JavaScript (fetch)

const res = await fetch("https://eol.org/api/pages/1.0/1045608.json?details=true");
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://eol.org/api/pages/1.0/1045608.json?details=true", timeout=20)
res.raise_for_status()
print(res.json())

Response — HTTP 200 (truncated)

{
  "taxonConcept": {
    "identifier": 1045608,
    "scientificName": "Apis mellifera Linnaeus, 1758",
    "richness_score": null,
    "taxonConcepts": [
      {
        "identifier": 13331793,
        "scientificName": "Apis mellifera",
        "name": "Apis mellifera",
        "nameAccordingTo": "Eswatini Species List",
        "canonicalForm": "<i>Apis mellifera</i>",
        "sourceIdentifier": "T104184",
        "taxonRank": "species"
      },
      {
        "identifier": 14722330,
        "scientificName": "Apis mellifera",
        "name": "Apis mellifera",
        "nameAccordingTo": "Jordan Species List",
        "canonicalForm": "<i>Apis mellifera</i>",
        "sourceIdentifier": "T101866",
        "taxonRank": "species"
      },
      {
        "identifier": 17218442,
        "scientificName": "Apis mellifera",
        "name": "Apis mellifera",
        "nameAccordingTo": "Afghanistan Species List",
        "canonicalForm": "<i>Apis mellifera</i>",
        "sourceIdentifier": "T106313"
      },
      {
        "identifier": 22203556,
        "scientificName": "Apis mellifera",
        "name": "Apis mellifera",
        "nameAccordingTo": "CalPhotos",
        "canonicalForm": "<i>Apis mellifera</i>",
        "sourceIdentifier": "27e12bcc7bdcc623acb0a53562a1c043"
      },
      {
        "identifier": 24986578,
        "scientificName": "Apis mellifera Linnaeus 1758",
        "name": "Apis mellifera Linnaeus 1758",
        "nameAccordingTo": "NBII images",
        "canonicalForm": "<i>Apis mellifera</i>",
        "sourceIdentifier": "d2cfae8796fac8b1d518acc5a4506711

Parameters

Parameter	Type	Required	Description
`id`	path segment	Required	EOL page identifier for the taxon. `1045608`
`details`	query	Optional	Include text objects such as descriptions and habitat notes. `true`
`images_per_page`	query	Optional	How many images to include. Zero keeps the response small. `3`
`texts_per_page`	query	Optional	How many text objects to include. `2`
`common_names`	query	Optional	Include vernacular names with language codes. `true`
`synonyms`	query	Optional	Include synonymous scientific names. `true`
`taxonomy`	query	Optional	Include hierarchy entries from contributing classifications. `true`

Response fields

taxonConcept.identifierinteger: The EOL page id, echoing your request.
taxonConcept.scientificNamestring: EOL's preferred scientific name, including the authority.
taxonConcepts[]array: One entry per contributing source, each with its own identifier, `nameAccordingTo` and `sourceIdentifier`. This is the cross-reference map.
taxonConcepts[].nameAccordingTostring: Which source asserts this concept — a national species list, a museum collection, a checklist.
taxonConcepts[].canonicalFormstring: Name with HTML italic markup, ready to render.
dataObjects[]array: Text, image and video objects when requested, each with its own licence and attribution fields.

What you can build with the Encyclopedia of Life API

Show a species summary with images on a nature or education site
Cross-reference a taxon to identifiers in many other biodiversity databases
Pull licensed species photographs with correct attribution
Fetch trait data such as body mass or habitat from TraitBank
Look up vernacular names across languages

Common errors and how to fix them

404

Unknown page id.

Fix: EOL page ids are its own; resolve a scientific name through the `/search` endpoint first rather than guessing.

Sparse response

Optional content was not requested.

Fix: Descriptions, images and names are all opt-in. Add `details=true`, `images_per_page` and `common_names` as needed.

429

Anonymous rate limit exceeded.

Fix: Create a free EOL account for an API key, which raises the allowance considerably.

Image reuse uncertainty

Media licences vary by contributor.

Fix: Read the licence and attribution fields on each `dataObject`. EOL aggregates content under many different Creative Commons terms, and some are non-commercial.

Encyclopedia of Life API — frequently asked questions

Is the Encyclopedia of Life API free?

Yes, and it works without a key. A free account key is available and raises the rate limit, but it is not required. Content licences vary by contributor and are declared per item.

Can I use EOL images on my site?

Sometimes, and you must check each one. EOL aggregates media from hundreds of contributors under a mixture of Creative Commons licences, some of which exclude commercial use or require share-alike. The licence and attribution are on every media object.

What is TraitBank?

EOL's structured trait database — sourced, machine-readable measurements and categorical facts such as body mass, lifespan, diet and habitat. It is unusual among biodiversity APIs and is accessible through the same page endpoints.

How do I find an EOL page id from a species name?

Use the `/search` endpoint with the scientific name; it returns candidate pages with their ids. EOL ids are internal and do not correspond to GBIF keys, ITIS TSNs or any other registry's identifiers.

Tools that pair with this API

JSON Formatter

Format, beautify and minify JSON online with 2-space, 4-space or tab indentation. Sort keys alphabetically and catch syntax errors instantly — free and private.

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.

JSON Viewer

View JSON as a collapsible interactive tree online. Expand and collapse nodes, search keys and values, and copy the JSONPath of any node privately.

Encyclopedia of Life 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.