FilterLists API

Beginner's Pick Security / No Auth Required Beginner HTTPS

Free to Use

87 A

Metadata Score Metadata estimate · not endpoint-tested

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Overview

FilterLists is a community-maintained directory API that catalogs hundreds of filter lists used by ad blockers and firewalls like uBlock Origin and Pi-hole. You can query it to get metadata about filter lists including their names, URLs, languages, and the software they target. It is useful for building ad-block management tools or staying current with the filter list ecosystem.

Beginner Tip

FilterLists has no authentication — just call the REST API endpoints directly. Start with GET /api/v1/lists to retrieve all known filter lists and their metadata in one call.

Available Data

The kind of data this API exposes, based on its documentation. We could not call the endpoint to confirm the exact field names.

FilterLists data via REST API

Example Response

Illustrative shape only — we were not able to call this endpoint (it requires credentials or exposes no public sample URL), so the fields below show the kind of data this API returns rather than a recorded response.

JSON Response · Illustrative

{
  "status": "success",
  "data": {
    "result": "Data from FilterLists",
    "description": "Lists of filters for adblockers and firewalls",
    "timestamp": "2025-01-15T10:00:00Z"
  }
}

Field Reference

id Unique numeric identifier for the filter list.

name Human-readable name of the filter list.

description Brief explanation of what the filter list blocks or filters.

homeUrl Homepage URL where the filter list is officially maintained.

onDiskSizeKb Approximate file size of the filter list in kilobytes.

syntaxes List of filter syntaxes supported, such as AdBlock or hosts.

Implementation Example

Calls a real endpoint of this API. Replace any placeholder credentials with your own key.

Request

const url = "https://filterlists.com/api/v1/lists";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.

404 Not Found The filter list ID specified in the URL does not exist.

✓ First fetch all lists from /api/v1/lists to get valid IDs, then use those IDs for detail requests.

Slow response The full lists endpoint returns a large payload with hundreds of entries.

✓ Cache the response locally and refresh it periodically rather than calling the API on every user request.

CORS error in browser Some endpoints may not support cross-origin requests from all domains.

✓ Proxy the API call through your own backend server to avoid browser CORS restrictions.

Metadata Score Breakdown

Estimated from metadata — endpoint not independently tested

This score is estimated from observable metadata — HTTPS support, authentication model, declared CORS, and documentation reachability — because the API requires authentication or exposes no publicly testable endpoint. The five-signal breakdown is only shown for live-tested APIs.

Metadata estimate · endpoint not independently tested

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