Validate Lead Lists Before You Dial or Send
Stale and invalid records waste rep hours and wreck email deliverability. 1Lookup validates every phone number and email address in your list — in bulk or in real time — so you only contact people who actually exist.
20–30%
Of contact data decays each year
0–100
Deliverability score per address
~245ms
Per email verified
Why dirty lists cost you
Every disconnected number and dead inbox in your list is wasted spend — and a slow drag on your team’s results.
Dead numbers waste rep time
Disconnected lines, wrong numbers, and landlines kill dialer productivity and crush agent morale before a single real conversation happens.
Bad emails wreck deliverability
Invalid, disposable, and spam-trap addresses spike your bounce rate and get your sending domain blocklisted by mailbox providers.
You pay to reach people who don’t exist
Stale and fabricated records mean you’re spending budget — and burning sender reputation — on contacts that can never convert.
How 1Lookup cleans your list
Run your existing list through the API or validate at the point of capture, then keep only the records that are real and reachable.
Validate emails and phones in bulk or real time
Process your existing CRM list in bulk, or validate each record at the point of capture in your forms — same API, either way.
Filter on deliverability and line type
Drop disposable addresses, spam traps, disconnected numbers, and landlines; keep deliverable emails and dialable mobiles.
Hand reps and ESPs only contactable records
Sync the clean results back into your CRM and sending platform so every dial and every send reaches a real person.
// Clean a lead before your reps dial or your ESP sends
const res = await fetch('https://api.1lookup.io/v1/validate/email', {
method: 'POST',
headers: {
'Authorization': 'Bearer YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({
email: 'lead@prospect.com',
check_deliverability: true,
check_disposable: true
})
})
const { result, deliverability_score, disposable } = await res.json()
// Keep only deliverable, real contacts
const keep = result === 'valid' && !disposable && deliverability_score >= 80Products that power this
Mix and match the APIs you need. Each one works on its own or together in a single request.
Frequently asked questions
Why should I clean a lead list before dialing or sending?
Lead data decays 20–30% per year. Cleaning removes disconnected numbers, invalid and disposable emails, and spam traps so your reps spend time on real prospects and your emails stay out of the spam folder.
Can 1Lookup validate both phone numbers and email addresses?
Yes. You can validate emails for deliverability and disposable status, and validate phones for line type, reachability, and DNC status — either in bulk or in real time as records are captured.
Will list cleaning improve my email deliverability?
Removing invalid addresses and spam traps lowers your bounce rate and protects your sender reputation, which directly improves inbox placement with mailbox providers.
Can I clean my existing CRM list in bulk?
Yes. Upload your list for bulk validation or call the API per record, then sync the verified results back into your CRM or sending platform.
How fast is validation?
Email validation returns in roughly 245ms per record and phone validation in under 300ms, so you can validate at the point of capture without slowing down your forms.
Dial and send with confidence
Validate every phone and email in your list so your team only spends time on contacts that are real and reachable.
No setup fees • 100 free validations • Cancel anytime