Email and phone validation APIs compared

What we compared, and what we left out

Email verification and phone validation are different jobs. Email verification tries to tell you whether a mailbox will accept a message. Phone validation checks a number's format and, with more data, its line type or carrier. We cover the vendors whose pricing page we could read on the read date and show the packs those pages list. Vendors whose prices we could not read plainly on their own page that day are not in the tables.

Prices exclude tax, vary with currency and billing period, and change, so use the table to shortlist and the vendor page to buy.

Email verification: price per thousand

The pack prices are as listed. The last column is the pack price divided by the number of verifications, times 1,000. Kickbox was running a time-limited discount code on the day we read its page; the figures here are its list prices.

Phone validation: price per thousand

Phone pricing mixes per-request fees, credit packs and plans, and the products behind the price differ. Twilio charges for line type intelligence per request and says basic formatting and E.164 country code validation are free. Veriphone counts one credit for a standard validation and ten for a current-carrier lookup, so the per-thousand figure below is for standard validation only.

What LookValid does and does not do

LookValid is one API key and one credit balance across many lookups. The numbering-plan phone check and the Email Domain Check cost one credit each, and other products are listed at their own credit counts. The plans below are the self-serve ladder; the per-thousand figure assumes you use every credit in the month.

On the email side, LookValid's Email Domain Check looks at the domain behind an address: MX records, SPF and DMARC policies, and whether it is a disposable domain, a free mailbox provider or a role address. It never contacts the mail server, so it cannot confirm that a mailbox exists. If you need mailbox-level results, use a dedicated verifier from the first table. On the phone side, LookValid's phone product checks a number against its country's numbering plan and returns formats, the country and the number type the plan assigns. It does not query carriers, so it cannot say whether a number is active, ported or reachable. Its carrier lookup returns the carrier originally assigned a US number block and does not reflect porting. A Phone Spam Check returns reported-caller complaints from public FTC and FCC data.

A worked cost: ten thousand phone numbers

Say you want to validate 10,000 phone numbers once. At Twilio's per-request line type price that is $80. At Veriphone's 10,000-credit pack it is $24, for standard validation. A LookValid entry-plan month costs $99 and holds 20,000 credits, so 10,000 lookups use half of them and the effective price for this one job is $9.90 per thousand. A specialist pack is cheaper for a one-off job on price alone, and a plan makes more sense when you check records every month across several kinds of lookup.

Price is only part of it. Compare what each result tells you: format and numbering-plan type, carrier line type, or live line status are different products, and the same word on a pricing page can cover different things.

Choosing one

Match the tool to the failure you want to prevent.

• Cold email lists: a mailbox-level verifier. ZeroBounce, Kickbox and Bouncer each state that unknown results are not charged or are refunded, and MillionVerifier lists its credits as non-expiring.
• Checking a number is plausible before you store it: a numbering-plan check, which is free at Twilio and one credit at LookValid.
• Line type for routing calls or texts: a carrier-backed lookup from a vendor that states what it queries.
• Several lookup types behind one key: a provider that sells several lookup types, such as LookValid or Abstract API, accepting that the price per check is higher than a single-purpose specialist.
• Anything you automate: test with a sandbox key first where the vendor offers one. Kickbox documents a sandbox mode that returns mock results without deducting credits.

Corrections

Vendors change their prices and packs often. If a figure here no longer matches a vendor's page, the vendor's page is right.

Spot something wrong or out of date? Write to hello@meralume.com and we will review it.