Compare/Head to head

Instantly vs Underfive

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

Starting price

Instantly

$37.60/mo Free trial

Cold-email infra for teams farming many sending mailboxes. Outreach Growth is $37.60/mo billed yearly, or $47/mo monthly.

Where Instantly fits

  • Outbound recruiting teams sending at volume
  • Agencies running many sending accounts
  • Desks that need warmup plus a unibox
  • Recruiters who want an agent to find candidates and send first outreach

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

DetailInstantlyUnderfive
Starting price$37.60/mo$60/mo
Free tier–No–No
Free trialYesYes
MCP server✓Yes✓Yes
Public API✓Yes✓Yes
Listed underOutreachOutreach, Workflow automation

Where they pull apart

Instantly

Stands out: Warmup, unibox, and volume send with hosted MCP and a public API, plus an AI Recruiting Agent that finds candidates from a job link and emails them.

Watch out: Deliverability still depends on your domains and inboxes, not the tool alone.

Not the right fit for

  • Teams that only need LinkedIn messaging
  • Buyers looking for an ATS

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

Instantly

  • Warmup and unibox in the same desk
  • AI Recruiting Agent sources candidates and drafts outreach from a job link
  • Hosted MCP plus REST API
  • No-card get-started path on the vendor site
  • Sending domains and inboxes are bought separately
  • Sequence designer is plainer than multichannel rivals
  • Volume tiers step up quickly as mailboxes grow

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

Instantly

$37.60/mo

Outreach plans: Growth $37.60/mo billed yearly, or $47 monthly, for 5,000 emails and 1,000 contacts; Hypergrowth $85.58/mo yearly, or $107 monthly, for 125,000 emails and 25,000 contacts; and Light Speed $286.30/mo yearly, or $358 monthly, for 500,000 emails. Lead credits are a separate plan from $47/mo, and bundles of both start at $94/mo. Every plan has unlimited email accounts and warmup. 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 Instantly cheaper than Underfive?
Instantly starts lower, at $37.60/mo 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 Instantly or Underfive for free?
Neither carries a free tier on our listing. Instantly offers a free trial. Underfive offers a free trial.
Does Instantly or Underfive have an MCP server?
Instantly and Underfive ship 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?