Verify inputs. Watch important facts.
One API key, one credit balance, and evidence that never pretends to be certainty.
See the answer and its boundary.
Choose a sample, run the check, and see exactly what comes back. The homepage uses demo data and never spends credits.
- Syntax
- Valid
- Mail exchange
- Found
- Address type
- Role address
- Mailbox
- Not checked
One job: reduce bad decisions.
Every result states what was checked, when it was checked, and what it does not prove.
Email Check
Catch broken, disposable, role-based, and free-provider addresses before they pollute your workflow.
02 · /v1/vat/checkVAT Check
Validate an EU VAT number against VIES and keep the timestamp and request evidence.
03 · /v1/iban/checkIBAN Check
Normalize an IBAN and verify its country structure, length, and checksum locally.
04 · /v1/cpsc/recall-matchCPSC Recall Watch
Match product identity against U.S. recalls and Product Safety Warnings, then keep catalogs under watch.
05 · /v1/knowledge/watchesKnowledge Watch
Watch named facts on public static web pages and receive a webhook only when meaning changes.
FREE HELPERDomain Check
DNS, MX, TLS and RDAP signals for registrable domains. Free up to 100 checks per workspace each day.
Ignore noise. Keep the change.
LookTwice records quiet checks in the background and sends a webhook only when a named fact meaningfully changes.
Meaningful change found
From input to evidence in three moves.
Use the same authentication, billing, event history, and webhook signature across every product.
Create one API key
Scopes, rotation, spend caps, and per-workspace rate limits are built in.
Send a real input
Charged requests are idempotent. Retries never silently spend twice.
Keep the evidence
Source, timestamp, content hash, and honest status travel with the result.
Use any API. Pay for the work.
Every monthly plan includes one balance for all APIs. The allowance resets at the end of its billing period.