Abstract API

Abstract API is a library of single-purpose REST APIs that teams use to verify users, block fraud, and enrich records. The endpoints most relevant to revenue teams are email validation, email reputation, phone validation, and company enrichment, alongside IP intelligence and geolocation for lead routing and risk scoring. Its email validation API runs syntax, MX, live SMTP, disposable, catch-all, role, and typo checks in a single call and returns a quality score in under 300 milliseconds, which teams use to clean lists before sending and to block bad addresses at signup. Each API is sold as its own subscription with its own key and free tier, and the platform connects to Salesforce, HubSpot, Marketo, Zapier, Make, Snowflake, and the major cloud providers. Abstract states that it has processed more than 3 billion validations, holds SOC 2 Type II certification and GDPR readiness, and offers a 99.99% uptime SLA on enterprise plans.

Features

• Email Validation: Combines syntax, MX, live SMTP, disposable, catch-all, role, and typo checks with a quality score in one request.
• Email Reputation: Adds sender, domain, and risk detail including domain age, DMARC and SPF status, spam trap and toxic domain flags, and known breach history.
• Phone Validation: Verifies phone numbers and flags invalid, VoIP, and disposable lines to raise contact rates on calling lists.
• Company Enrichment: Returns firmographic data such as headcount, location, and industry from any domain or email address.
• IP Intelligence and Geolocation: Geolocates any IP and surfaces risk signals including VPN, proxy, and abuse history for routing and fraud checks.
• Real-Time and Bulk Modes: The same checks run inline through a REST call or as bulk CSV uploads, supported by SDKs, code samples, and 24/7 technical support.

Pricing

Abstract prices each API separately, with a free tier per product and a 10% discount for annual billing. The Email Validation API is priced as follows:

• Free: $0. 100 requests with the full validation response and no credit card required.
• Starter: From $17/month for 5,000 requests, covering deliverability checks with domain whitelisting and bulk CSV upload.
• Standard: From $37/month, adding sender and domain data such as organization name, domain age, and registrar details.
• Professional: From $39/month, adding quality scoring, risk status, and breach data, with volumes scaling from 5,000 to 150,000 requests per month.
• Enterprise: Contact for details. Flexible request volumes and rate limits, commercial licensing, enhanced SLA and support, and a dedicated account manager.

Phone validation, company enrichment, IP intelligence, and the other APIs carry their own plans, so teams using several products hold several subscriptions.

Pros

• Fast Integration: A single REST call returns structured JSON, and dashboard testing plus code samples get a first request into production quickly.
• Depth in One Response: Deliverability, quality score, sender and domain details, risk status, and breach history return together rather than across several lookups.
• Free Tier on Every API: Each product includes a no-card allowance, so teams can benchmark accuracy against their own data before paying.
• Low Entry Cost: Email validation starts at $17 per month for 5,000 checks, which the company positions below several dedicated verification vendors.
• Enterprise Compliance: SOC 2 Type II, GDPR readiness, SSO and SAML login, and a 99.99% uptime SLA support use in regulated environments.
• Broad Stack Coverage: Integrations span Salesforce, HubSpot, Marketo, Pardot, Zapier, Make, Snowflake, Shopify, AWS, Azure, and GCP.

Cons

• Separate Subscription Per API: Products are keyed and billed independently, so a team needing validation, enrichment, and phone checks carries three bills.
• Throughput Limits on Standard Plans: Published tiers list three requests per second, which slows bulk verification of large lists without careful batching.
• Catch-All Domains Stay Unresolved: Addresses on catch-all domains are flagged rather than judged, leaving the final call to the user.
• Developer-First, Not Sales-First: There is no campaign, list management, or prospecting layer, so non-technical teams need an automation tool or engineering help.
• Validation Only: The platform checks and enriches data a team already holds; it does not source contacts or build prospect lists.
• Limited Public Review Coverage: Independent review volume is small relative to established email verification vendors, giving buyers less third-party evidence.