6sense vs Apollo.io: pricing, features and which to choose

6sense was founded in San Francisco in 2013 and grew into one of the two largest account-based marketing (ABM) vendors, alongside Demandbase. It raised a $200 million Series E in 2022 at a $5.2 billion valuation. The product watches anonymous research activity across the web, matches it to companies, and tells sellers and marketers which accounts are likely in market and how far along they are. 6sense now calls itself an intelligence engine for agentic go-to-market, and most 2026 releases push its data into other tools, including Claude, ChatGPT and Salesforce Agentforce, instead of asking users to live in its dashboards.

The platform splits into Revenue Marketing and Sales Intelligence. On the marketing side, teams define keywords and personas, 6sense scores accounts into buying stages, and the system builds segments for display and LinkedIn ads, website personalization and email. An account that crosses a threshold becomes a 6QA, or 6sense Qualified Account, and is routed to sales. Sales Intelligence gives reps account pages, a Chrome extension that works inside LinkedIn, Sales Navigator, Salesforce, Salesloft and Outreach, alerts, buying-group discovery and contact data. Credits buy access to emails and phone numbers and power list building. AI Email Agents can write, send and reply to prospecting emails based on intent signals.

The common complaints are cost, a long setup before predictions become trustworthy, and intent signals that some buyers find noisy for niche categories. Contact data coverage outside North America draws criticism on review sites. Demandbase is the closest rival, with similar intent and advertising features and a median contract slightly higher, at about $68,600 according to Vendr. ZoomInfo leads on contact data and is often bought for that alone. Clay and Apollo cover account research and outreach at published prices from under $100 a month. 6sense fits B2B companies with enough deal volume and ad budget to act on account scoring; small teams should start with Apollo or Clay.

Apollo.io is a sales intelligence and go-to-market platform made by ZenLeads, Inc., doing business as Apollo.io. Founded in 2015, it released its first product in 2016 and says it reached $150 million in annual recurring revenue in May 2025. Apollo also reports more than 500,000 companies using the platform and more than 50,000 weekly active users in 2025. Its 2023 Series D raised $100 million at a reported $1.6 billion valuation. The product combines a business contact database with prospect search, enrichment, sequencing, calling, pipeline support, analytics, and AI features. That combination places Apollo closer to a sales operating system than a standalone lead database, serving founders, sales teams, marketers, and revenue operations groups.

Apollo’s workflow usually begins with finding people or companies through filters, then selecting records for enrichment, lists, sequences, or exports. Email campaigns are available on every account. Free users can connect Gmail, while paid users can connect Microsoft Office and other providers. Teams can create sequences, manage pipeline activity, record calls, prepare for conversations, and review AI-generated insights. The AI Assistant accepts natural-language requests, uses Apollo data and saved messaging context, and can find decision-makers, research accounts, build sequences, export lists, and report on performance. Scheduled agents can run some outbound tasks in the background. Permissions still govern available actions, and Apollo advises reviewing generated messages, matches, and credit estimates before execution.

Apollo’s main limitation is pricing and usage complexity: the final amount depends on seats, billing frequency, credits, add-ons, and selected features. Basic includes one mailbox, 250 daily emails, five team workflows, and 1,000 records per selection, while Professional raises several limits and adds AI and call features. Standard plans are for internal business use, so powering external products, sharing data with customers, or reselling it requires a separate agreement. Apollo competes with ZoomInfo, Cognism, Outreach, Salesloft, and HubSpot Sales Hub. It combines data and enrichment more closely than Outreach or Salesloft, and adds execution tools beyond ZoomInfo or Cognism. Choose Apollo if one team needs prospect intelligence, outbound execution, enrichment, and AI actions together.