BYTETOOLS

DeBounce Disposable Check API

Free disposable-email check with no key: pass an address, get back a single boolean saying whether the domain is a throwaway provider. Tested example included.

No API key requiredCORS enabledHTTPSFree tier

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

What is the DeBounce Disposable Check API?

DeBounce's disposable endpoint is a free, key-free check that tells you whether an email address belongs to a temporary or throwaway mail provider. The response is a single field, `disposable`, returned as the string "true" or "false".

This is the smallest useful anti-abuse check there is. One GET, one query parameter, one field back. It does not verify that the mailbox exists, it does not check syntax, and it will not tell you whether the domain accepts mail — it answers exactly one question, which is whether the domain behind the address is a known disposable-mail provider.

One detail catches people out: `disposable` comes back as a JSON *string*, not a boolean. `"true"` and `"false"` are quoted, so a naive `if (data.disposable)` in JavaScript is true in both cases and your check silently passes everything. Compare against the string, or coerce it explicitly. DeBounce sells a full validation API on top of this, but this particular endpoint needs no key and no account.

Quick facts

Base URL
https://disposable.debounce.io
Authentication
No API key and no account for the disposable check. DeBounce's fuller validation product is a separate, paid service.
Rate limit
No published limit, but this is a free courtesy endpoint — keep volumes sane and cache by domain.
Pricing
Free.
CORS
Enabled — callable directly from browser JavaScript
Official docs
Read the docs

How to use the DeBounce Disposable Check 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. Check whether an address is a throwaway

GET https://disposable.debounce.io/?email=test@mailinator.com

curl
curl 'https://disposable.debounce.io/?email=test@mailinator.com'
JavaScript (fetch)
const res = await fetch("https://disposable.debounce.io/?email=test@mailinator.com");
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://disposable.debounce.io/?email=test@mailinator.com", timeout=20)
res.raise_for_status()
print(res.json())
Response — HTTP 200
{
  "disposable": "true"
}

Parameters

ParameterTypeRequiredDescription
emailqueryRequiredThe full email address to test. Only the domain part actually matters. test@mailinator.com

Response fields

disposablestring
The string `"true"` or `"false"` — quoted, not a JSON boolean. Compare as a string or coerce before using it in a conditional.

What you can build with the DeBounce Disposable Check API

  • Block throwaway addresses at signup for a free trial
  • Score lead quality before pushing a contact into a CRM
  • Clean an existing mailing list of dead disposable domains
  • Gate a discount code or referral bonus behind a real address

Common errors and how to fix them

Check always passes in JavaScript

`disposable` is the string "false", which is truthy.

Fix: Use `data.disposable === "true"`. This is the single most common mistake with this endpoint.

Missing `email`

The parameter was omitted.

Fix: It is required. A bare domain will not work — send a full address.

False negative on a new provider

The domain list has not caught up with a newly registered disposable service.

Fix: No blocklist is ever current. Combine with an MX check and, for high-value flows, a verification email.

DeBounce Disposable Check API — frequently asked questions

Is the DeBounce disposable check really free?

Yes. This one endpoint needs no key and no signup. DeBounce's full email-validation product, which does mailbox-level verification, is a separate paid service.

Why is `disposable` a string and not a boolean?

That is simply how the endpoint serialises it. Because `"false"` is a truthy string in JavaScript and PHP, comparing loosely makes every address pass — check against the literal string instead.

Does it confirm the mailbox exists?

No. It only answers whether the domain is a known disposable provider. A real-looking address on a permanent domain can still bounce.

Can I call it from the browser?

Yes, it sends a permissive CORS header. There is no key to leak, so front-end use is safe.

Tools that pair with this API

DeBounce Disposable Check 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.