Compare/Head to head

AiSDR vs Underfive

Same facts, side by side: starting price, free tier, MCP, API and what each one is actually built for.

Starting price

AiSDR

$1.50/person prospected

AI SDR that prospects on signals, runs email and LinkedIn, and books meetings (Ami). Pay as you go is $1.50 per person prospected; no free trial.

Where AiSDR fits

  • Founder-led sales that want an AI SDR with a public price
  • HubSpot or Salesforce shops
  • Teams comparing Ava and Ami
  • Buyers who will not wait on a quote

Underfive

$60/mo Free trial

Underfive puts every cold email and LinkedIn reply in one inbox and has AI agents answer them in under five minutes and book the meeting. It suits agencies and recruiting firms running outbound for clients who lose meetings to slow replies. Plans start at $60 a month for 200 credits, and new accounts get 50 free credits with no card.

Where Underfive fits

  • Agencies booking meetings for several clients
  • Recruiters who miss replies outside working hours
  • Teams running both cold email and LinkedIn outreach
  • Teams that want AI drafts approved in Slack

At a glance

DetailAiSDRUnderfive
Starting price$1.50/person prospected$60/mo
Free tier–No–No
Free trialNot on recordYes
MCP server–No✓Yes
Public API–No✓Yes
Listed underLead generation, OutreachOutreach, Workflow automation

Where they pull apart

AiSDR

Stands out: A public $1.50 per person pay-as-you-go plan with HubSpot, Salesforce, Close, Clay and Calendly named, and cancel-anytime terms.

Watch out: Team plans for 1,000+ people a month are priced on volume through sales. No free trial is named. Per-campaign managed service is extra.

Not the right fit for

  • People who need a $40 sequencer
  • Teams that insist on a free trial
  • Enterprises that want a fully managed $2,500 desk on day one without testing pay as you go

Underfive

Stands out: Pricing follows the replies its agents handle rather than seats or mailboxes, so a small desk can start at $60 a month where Master Inbox starts at $599. It also ships its own hosted MCP server, so an AI assistant like Claude can read threads and approve or send replies.

Watch out: Credits run out faster on high volume or chatty threads, since every reply read costs half a credit and every draft costs one. The API, webhooks and MCP server start on the $150 Growth plan, and the entry plan has a single workspace.

Not the right fit for

  • Teams that want flat pricing regardless of volume
  • Senders who want no automated replies at all
  • Users who need API access on the entry plan

Pros and cons

AiSDR

  • Public $1.50 per person pay-as-you-go price instead of a pure quote
  • HubSpot, Salesforce, Close, Clay named
  • Sign up without a credit card
  • No free trial
  • Team plans are sales-quoted on volume
  • Per-person billing adds up at volume

Underfive

  • Low entry price, priced per reply
  • Email and LinkedIn in one inbox
  • Hosted MCP server and API
  • Credits can run out at volume
  • API and MCP from $150 a month
  • One workspace on the entry plan

What each one costs

AiSDR

$1.50/person prospected

Pay as you go is $1.50 per person prospected, charged daily, with no contract and cancel anytime. Team plans for 1,000+ people a month are priced on volume through sales, billed monthly on quarterly contracts, with 20% off annual. Add-ons include a warmed-up mailbox at $33, a per-campaign managed service at $149 and a fully managed service at $2,500/mo. No free trial is named; you can sign up without a credit card. Confirm current terms on the vendor site.

Checked 4 Nov 2026

Underfive

$60/mo

Underfive prices on credits used by its agents, not on seats or mailboxes: reading a reply costs 0.5 credits and drafting a response costs 1 credit. Professional is $60 a month for 200 credits and one workspace. Growth is $150 a month for 500 credits and five workspaces and adds the API, webhooks and MCP server. Business is $250 a month for 1,000 credits and ten workspaces. Agency is $500 a month for 2,500 credits, unlimited workspaces and custom integrations. Paying annually saves 20%, custom plans are available above 2,500 credits, and a managed service is offered where the vendor's team works the inbox. New accounts start with 50 free credits and no credit card. Confirm current terms on the vendor site.

Checked 4 Nov 2026

Common questions

Is AiSDR cheaper than Underfive?
AiSDR starts lower, at $1.50/person prospected against $60/mo for Underfive. That is the entry plan on each side, so the real number depends on seats and the tier you land on.
Can you try AiSDR or Underfive for free?
Neither carries a free tier on our listing. Underfive offers a free trial.
Does AiSDR or Underfive have an MCP server?
Underfive ships a first party MCP server, so an AI assistant can work the product directly.

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Editorial listings, never paid rankings. Prices checked 4 Nov 2026. Confirm current terms on the vendor site. Spot an error?