Free caller-ID & spam pre-screen

Is your number flagged as spam?

Validate any US number, detect its line type, and pre-screen caller-ID spam risk in seconds — then get the live, continuous carrier-reputation read inside ReadySMS. Check up to 50 numbers at once.

Paste one number per line (up to 50). US/Canada numbers, any format — e.g. (415) 555-0142 or +1 415 555 0142.

Runs entirely in your browser. We don’t store, send, or see the numbers you paste here.

Want the real carrier-reputation read?

This pre-screen checks what your browser can see — format, line type, and risk patterns. The live “Scam Likely / Spam Risk” status comes from carrier and analytics databases (Verizon, T-Mobile, AT&T, Nomorobo, Hiya). ReadySMS monitors your numbers continuously, shows a health badge on each, and can auto-rotate a flagged number for a clean one.

Get live monitoring free — 2,500 SMS on us →

What this checker looks at

An instant, honest pre-screen of every number — no signup, no data stored.

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Format & validity

Confirms the number is a valid North American (NANP) number with a real area code and exchange — catching typos, wrong digit counts, and invalid ranges before they cost you a send.

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Line type

Flags toll-free numbers (800/888/877/866/855/844/833) that need separate verification, premium/special ranges, and standard local long codes used for 10DLC texting.

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Spam-risk patterns

Surfaces patterns that often correlate with throwaway or flagged ranges — repeated or sequential digits and other low-trust signals — so you know which numbers to watch.

A browser-based pre-screen can’t read live carrier reputation — that requires a carrier-grade lookup. Get the live read inside ReadySMS →

Questions & answers

How do I check if my phone number is flagged as spam?
Paste it above. This tool instantly validates the number, detects its line type, and pre-screens for spam-risk patterns. For the live “Scam Likely / Spam Risk” status across carrier and analytics databases, connect the number inside ReadySMS — it monitors reputation continuously and shows a health badge on each number. Start free →
Why do my texts or calls get marked “Scam Likely”?
Carriers and analytics partners (First Orion, Hiya, Nomorobo) score numbers on volume, complaint rates, answer rates, and reports. High-volume outreach from a single unverified number, sudden spikes, or complaints can get it labeled — which tanks answer and delivery rates. ReadySMS catches this early and can auto-rotate the number for a clean one within a cap you set.
Is this checker really free?
Yes. The validation, line-type detection, and risk pre-screen run free in your browser with no signup and nothing stored. Live carrier-reputation monitoring and auto-rotation are included free inside a ReadySMS account.
Can I check several numbers at once?
Yes — paste up to 50 numbers, one per line. Inside ReadySMS you can monitor all of your sending and calling numbers continuously, not just spot-check them.
How is this different from the 10DLC checker?
The 10DLC checker predicts whether your A2P brand and campaign registration will be approved. This number health checker looks at the phone numbers themselves — validity, line type, and spam-reputation risk. Most senders need both.

Stop losing leads to a flagged number.

ReadySMS watches your sending and calling numbers around the clock, warns you before reputation drops, and swaps in a clean number automatically.

Start free — 2,500 SMS on us →