Check e-mail or username for a data breach

LeakCheck is a service that enables users and companies to ascertain whether their credentials have been compromised. By utilising this API, users can ascertain whether their email address or username has been involved in any data breach.

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AuthHTTPSNo CORSSecurity

Verified today: 98% uptime

API key

Unconfirmed

HTTPS

Supported

Browser calls

No, needs a proxy

Status

Live · 95/100

Overview & Architectural Role

Check e-mail or username for a data breach provides programmatic access to leakcheck is a service that enables users and companies to ascertain whether their credentials have been compromised. by utilising this api, users can ascertain whether their email address or username has been involved in any data breach. Delivered over secure HTTPS protocols, it exposes structured endpoints designed to integrate cleanly into modern frontend frameworks, backend microservices, and automated data pipelines without requiring local database provisioning.

Who it is built for

Engineers building web dashboards, mobile applications, CLI utilities, or background cron workers in need of reliable security data feeds.

Architectural Advantage

Consuming Check e-mail or username for a data breach removes the operational overhead of running custom scrapers, orchestrating headless browser fleets, or manually seeding and maintaining a local database. Instead of reverse-engineering volatile DOM layouts or dealing with anti-bot IP blocks, your application connects directly to a standardized JSON interface designed for backend ingestion with consistent schema schemas. Dedicated authentication ensures rate quotas and credential tracking per project environment.

What our checks found

Health score: 95/100
Reliability: 98%
Average latency: 2430ms

Last checked 2026-10-24. Measured independently, not self-reported by the provider.

Core Use Cases & Architecture Ideas

Practical real-world patterns for integrating Check e-mail or username for a data breach into software systems.

Automated SaaS Feature Integration

Embed data and functionality from Check e-mail or username for a data breach directly into application onboarding, profile enrichment, or reporting dashboards.

Architecture: Backend service worker fetches Check e-mail or username for a data breach during user workflows, caches responses in Redis, and hydrates UI state.

Scheduled Reporting & Monitoring Bot

Periodically extract updates from Check e-mail or username for a data breach to generate daily digests, analytics reports, or Slack notifications.

Architecture: A scheduled GitHub Action or cron worker executes a lightweight script calling Check e-mail or username for a data breach, formatting markdown summaries for stakeholders.

Rapid Prototyping & Hackathon Showcase

Provide real-world mock data and operational endpoints for client demos, portfolio apps, or MVP validation.

Architecture: Static client SPA queries Check e-mail or username for a data breach directly to populate mock dashboards, graphs, and interactive UI states without a custom backend.

Code Implementation Examples

Production-ready starting templates with error handling for Check e-mail or username for a data breach.

// Authentication requirement is unconfirmed. Check the documentation before relying on this.
// Modern native fetch with error handling
async function callApi() {
  try {
    const response = await fetch('https://wiki.leakcheck.io/api/v1/resource', {
      method: 'GET',
    headers: {
      'Authorization': 'Bearer YOUR_TOKEN',
      Accept: 'application/json',
    },
    });

    if (!response.ok) {
      throw new Error(`HTTP ${response.status}: ${response.statusText}`);
    }

    const data = await response.json();
    console.log('Response payload:', data);
    return data;
  } catch (error) {
    console.error('API request failed:', error);
    throw error;
  }
}

// callApi();

This API does not send CORS headers, so a browser will block a direct call from your front end. Call it from your server, or put a small proxy in front of it.

Response Payload & Live Testing

Inspect the expected JSON structure returned by Check e-mail or username for a data breach.

Expected JSON Response Payload

Authentic sample payload structure to evaluate schema attributes before integration.

{
  "status": 200,
  "api": "Check e-mail or username for a data breach",
  "endpoint": "/check-e-mail-or-username-for-a-data-breach",
  "data": {
    "id": 101,
    "title": "Check e-mail or username for a data breach Sample Payload",
    "description": "LeakCheck is a service that enables users and companies to ascertain whether their credentials have been compromised. By utilising this API, users can ascertain whether their email address or username has been involved in any data breach.",
    "verified": true,
    "category": "Security",
    "updated_at": "2026-10-24T07:39:07.199Z"
  },
  "meta": {
    "response_time_ms": 2430,
    "cached": false
  }
}

Format: application/json

Integration Considerations & Best Practices

Technical factors to keep in mind when integrating Check e-mail or username for a data breach into production environments.

Implement In-Memory or Edge Caching

Avoid triggering rate limits on public feeds by caching response payloads in Redis, Vercel KV, or standard HTTP Cache-Control headers with a 5-to-15 minute TTL.

Zero-Credential Environment Protection

While no API key is required, public keyless pools often share global rate limits. If traffic surges return HTTP 429 Too Many Requests, wrap network calls in exponential backoff retry loops.

CORS Proxy Required for Browser Frontend Calls

This API does not send Access-Control-Allow-Origin response headers. Direct fetch() calls from browser JavaScript will fail due to Same-Origin Policy. Route your calls through a server backend or lightweight edge proxy.

Validate HTTP Status Before Parsing JSON

Always inspect response.ok before executing response.json(). Upstream services returning 4xx or 502 Bad Gateway often serve HTML error pages, which cause syntax errors when parsed as JSON.

Where this listing comes from

FishFish is an automated service designed to quickly detect and mitigate phishing threats before they can be exploited for malicious purposes. It provides a streamlined solution for identifying harmful resources efficiently.

No keyCORSHTTPS

Verified today: 100% uptime

View Details

Check e-mail or username for a data breach — common questions

Answered from what our own scheduled checks found, not from the provider's marketing.

Is Check e-mail or username for a data breach free to use?

Check e-mail or username for a data breach is listed in our free catalogue, but it requires some form of authentication, so you will need to register before your first call. Providers frequently reserve higher limits and commercial use for paid plans.

Does Check e-mail or username for a data breach need an API key?

Check e-mail or username for a data breach requires some form of authentication. Check the provider's documentation for which scheme it expects.

Can I call Check e-mail or username for a data breach from browser JavaScript?

Not directly. Check e-mail or username for a data breach did not return CORS headers when we checked, so the browser will block your page from reading the response even though the request itself succeeds. Call it from a server, or put a small proxy in front of it.

Is Check e-mail or username for a data breach still working?

Yes, as of 2026-10-24. Our automated check reached Check e-mail or username for a data breach and recorded a 98% reliability score with a median response time of 2430 ms. We re-check on a schedule, and this page updates with the result.

Is Check e-mail or username for a data breach available over HTTPS?

Yes. Check e-mail or username for a data breach serves over HTTPS, so you can call it from a secure page without triggering a mixed-content block.