CheckNumber.AI 
Signal Checker
signal $4 per 10,000 checks
- Core data available
- number, activated
- Best for
- Privacy-conscious audience segmentation
No-code CSV REST API Exportable results
Check Signal Account Registration
Verify whether a phone number is registered on Signal, the encrypted messaging app.
Signal is a privacy-focused messaging app popular among users who prioritize end-to-end encryption, often alongside or instead of mainstream apps like WhatsApp. CheckNumber's Signal checker confirms whether a phone number holds a registered Signal account, useful for identifying privacy-conscious contacts or cleaning a list before a Signal-based outreach flow, without ever messaging the number.
E.164
Phone input
$4
Per 10,000 checks
CSV + API
Workflow
Submitted number +1917••••3382
Signal status yes / no
Signal Checker No account, number, or SIM required
Every check runs through official platform APIs on our own infrastructure. You never connect, bind, or use your own account, phone number, or SIM card — just upload your list or call the API and get results.
What CheckNumber detects for Signal
Signal account by phone
Confirms whether a phone number has a registered Signal account (yes or no).
Bulk yes/no verdict
Every number comes back with a clear registered or not-registered result, ready to filter and segment.
Passive, no contact
Reads registration signals only. The account holder is never messaged, logged in to, or notified.
What You Can Check
A focused Signal registration check
Use the Signal task when the required output is a row-level Signal-registration signal mapped to each submitted E.164 phone number.
| Signal product | Task type | Input | Core data available | Best for | Current price |
|---|---|---|---|---|---|
| Signal Checker API documentation | signal | Phone numbers in E.164 format | number, activated | Privacy-conscious audience segmentation | $4 per 10,000 checks |
Core Signal data
What the Signal task returns
The result file maps one row to each submitted number with the fields below.
Registration
signal - Number
- The phone number supplied for the check, in E.164 format.
- signal
- Whether the number is registered on Signal (yes or no).
The signal field is a boolean signal only — it does not include usernames, profile names, or message history.
Run a Signal batch in three steps
Use the no-code platform for uploaded lists or the REST API for recurring workflows.
- 1
Prepare E.164 numbers
Provide one international phone number per row with country code.
- 2
Create the signal task
Upload the file or call the API with task_type set to signal.
- 3
Export mapped rows
Download the completed file and match each result to its source number.
Common Use Case
Improve Signal list quality before outreach
Segment privacy-focused users for targeted, compliant outreach.
No-code CSV REST API Exportable results
Signal 1
Registration check — confirm in bulk whether each phone number is a Signal account.
Signal 2
List quality — keep only real Signal users and drop the rest before outreach.
Signal 3
Privacy-safe — a passive check that never messages, logs in, or notifies the account holder.
Signal FAQ
Can I check phone numbers against Signal in bulk?
Yes. Upload a CSV of up to hundreds of thousands of numbers or call the REST API, then download a result file with a registered or not-registered verdict for every number. You are billed only for successful checks.
Do you check by phone number or email?
Signal is checked by phone number. Upload a list of numbers and each is verified against Signal registration.
Does the check contact or notify the person?
No. The check is passive and reads registration signals only. Nothing is sent to the number, and the account holder is never contacted or notified.
Is there a free trial?
Yes. New accounts receive 1,000 free checks on signup with no credit card, and every check is pay-as-you-go with no monthly fee, and the credits you top up never expire.
Refer & Earn 10%
Earn 10% Commission on Every Recharge — For Life
Share your unique referral link. When someone signs up through it and tops up their account, you instantly receive 10% of the amount paid as bonus credit — no expiry, no cap.
- 10% commission on every recharge your referrals make
- Bonus credit is applied automatically — no withdrawal steps
- Lifetime referral link — earn forever, not just once
10%
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