B2B contact database plus sales engagement and AI prospecting platform.
Reply.io vs Seamless.AI
Features, pricing, strengths and trade-offs — and which one fits your situation.
The verdict
Summary
Reply.io is best for sales teams wanting multichannel sequences plus an optional autonomous AI SDR, while Seamless.AI is best for sales reps who mainly need verified emails and mobile numbers for prospecting. Reply.io has a medium learning curve, compared with low for Seamless.AI. Seamless.AI has a free plan, while Reply.io offers a free trial.
Which should you choose?
Choose Reply.io if…
- You need sales teams wanting multichannel sequences plus an optional autonomous AI SDR
- You're one of: sdr and bdr teams, sales agencies, companies testing ai sdr automation
- Covers many channels in one sequence
Choose Seamless.AI if…
- You need sales reps who mainly need verified emails and mobile numbers for prospecting
- You're one of: sdrs doing phone prospecting, recruiters, sales teams needing contact enrichment
- You want a free plan (Reply.io only has a trial)
- You want something quicker to learn
At a glance
| Reply.io | Seamless.AI | |
|---|---|---|
| Best for | Sales teams wanting multichannel sequences plus an optional autonomous AI SDR | Sales reps who mainly need verified emails and mobile numbers for prospecting |
| Free plan | Trial only | Yes |
| Starting price | From $49 | From $147/mo |
| Learning curve | Medium | Low |
| Platforms | Web, Chrome extension, API | Web, Chrome extension, API |
| Ideal for | SDR and BDR teams, Sales agencies, Companies testing AI SDR automation | SDRs doing phone prospecting, Recruiters, Sales teams needing contact enrichment |
Feature comparison
| Reply.io | Seamless.AI | |
|---|---|---|
| B2B contact database | 1B+ contacts | 1.3B+ contacts |
| Email sequences | Yes | Limited |
| Email warm-up | Yes | — |
| Unlimited sending accounts | AI SDR plans | — |
| LinkedIn steps | Yes | Chrome extension (prospecting only) |
| Built-in CRM | — | No |
| AI personalization | Yes | Yes |
| Dialer / calling | Yes | Yes |
| Email verification | Yes | Yes |
IncludedLimited / higher plansNot available— Not confirmed
Security & enterprise
| Reply.io | Seamless.AI | |
|---|---|---|
| Business / enterprise plan | Yes | Yes |
| SSO (SAML / OIDC) | — | Yes |
| SCIM user provisioning | — | — |
| SOC 2 | Type I | Type II |
| ISO 27001 | — | No |
| HIPAA (BAA available) | — | — |
| GDPR DPA | Yes | — |
| Data residency options | — | — |
| No training on your data | — | — |
| Audit logs | — | — |
| Admin controls | — | Yes |
| Deployment | Cloud | Cloud |
From each vendor's security documentation. "—" = not confirmed. What to ask vendors · Compare all tools
What each tool does
Reply.io
Reply.io is a sales engagement platform with sequences across email, LinkedIn, calls, SMS and WhatsApp, an embedded B2B contact database, and deliverability tools. Its Jason AI SDR agent can prospect, personalize, follow up and handle replies. It is used by SDR teams and agencies that want outreach and AI automation in one subscription.
Key features- Multichannel sequences: email, LinkedIn, calls, SMS and WhatsApp
- Reply Data B2B database with 1B+ contacts
- Jason AI SDR for prospecting, follow-ups and replies
- Email warm-up for connected mailboxes
- Built-in calling from sequences
- Two-way sync with Salesforce, HubSpot and Pipedrive
Seamless.AI
Seamless.AI is a B2B contact data platform that searches for and verifies emails and phone numbers in real time. It includes a Chrome extension for LinkedIn and company sites, Autopilot for background list building, an AI Writer, and an engagement hub for emailing and calling. It is used by SDRs, recruiters and sales teams focused on phone and email prospecting.
Key features- Real-time contact search with verified emails and mobile numbers
- Chrome extension that overlays contact data on LinkedIn and websites
- Autopilot for automated list building
- AI Writer for cold emails and sales copy
- Buyer intent signals and data enrichment
- Connect engagement hub with emailing, calling and tasks
Pricing
Reply.io
Free trial; paid from ~$49-59/user/mo annual (Email Volume); AI SDR from $500/mo
Seamless.AI
Free plan (50 lifetime credits); Basic ~$147/mo billed yearly; Pro/Enterprise quote-only
Prices last checked September 2026. Plans change often — confirm on each vendor's site.
Pros and cons
Reply.io
Strengths- Covers many channels in one sequence
- Large contact database built in
- AI SDR option for teams wanting more automation
- Deep two-way CRM integrations
- Per-user pricing adds up for larger teams
- AI SDR plans are sold separately and cost much more
- Interface has more settings to learn than simple senders
- No free plan, only a trial
Not ideal for: Solo founders sending only cold email may get a simpler, cheaper setup from Instantly or Smartlead.
Seamless.AI
Strengths- Large database with many mobile numbers
- Chrome extension fits a LinkedIn-first workflow
- Free plan to test data quality
- CRM enrichment keeps records up to date
- Free plan credits are lifetime, not monthly
- Higher tiers are quote-only and require annual contracts
- Outreach features are basic compared with dedicated sequencers
- Data accuracy complaints are common, so bounce rates vary
Not ideal for: Teams that want sequencing and deliverability tools in the same product should look at Apollo.io or lemlist.
Integrations
Reply.io
Seamless.AI
FAQ
What is the main difference between Reply.io and Seamless.AI?
Reply.io is built for sales teams wanting multichannel sequences plus an optional autonomous AI SDR; Seamless.AI is built for sales reps who mainly need verified emails and mobile numbers for prospecting.
Is Reply.io or Seamless.AI cheaper?
Reply.io starts from $49 and Seamless.AI starts from $147/mo (as of September 2026). On entry price, Reply.io is cheaper — but compare what each plan includes, since limits differ. Always confirm current pricing on each vendor's site.
Do Reply.io and Seamless.AI have free plans?
Seamless.AI has a free plan, while Reply.io offers a free trial.
Which is easier to use, Reply.io or Seamless.AI?
Seamless.AI is generally quicker to learn (Reply.io: medium, Seamless.AI: low learning curve).
What are good alternatives to Reply.io and Seamless.AI?
Other sales & outreach tools worth comparing include Apollo.io, Instantly.ai and HubSpot.
