Compare/Head to head

Instantly vs Master Inbox

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

Master Inbox

$599/mo

Master Inbox collects every cold email and LinkedIn reply from your sequencers into one AI-labeled inbox, with a separate workspace for each client. It suits outbound agencies and recruiting firms running business development across many mailboxes and clients. Plans start at $599 a month on annual terms billed monthly, and the vendor runs a free 7-day proof of concept on your own inboxes.

Where Master Inbox fits

  • Outbound agencies managing replies for many clients
  • Teams running several sequencers and LinkedIn tools at once
  • Agencies that want to give clients a scoped inbox login
  • RevOps leads tracking missed replies and response time

At a glance

DetailInstantlyMaster Inbox
Starting price$37.60/mo$599/mo
Free tier–No–No
Free trialYesNot on record
MCP server✓Yes–No
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

Master Inbox

Stands out: It reads the mailboxes themselves rather than relying on the sequencer's reply feed, so forwards, CC replies and replies from new addresses show up alongside the rest, which a sequencer unibox such as Instantly's can miss. Unlimited users on every plan and per-client workspaces with scoped client logins make it built for agencies that hand reply handling to a team.

Watch out: The entry price of $599 a month is high for a solo recruiter or a small desk, and month to month billing adds 25%. Native Salesforce sync is not available yet and runs through webhooks or the OutboundSync partnership, and AI usage is paid separately on your own model key.

Not the right fit for

  • Solo recruiters with a handful of mailboxes
  • Teams that need native Salesforce sync
  • Buyers who want a low monthly entry price

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

Master Inbox

  • Unlimited users on every plan
  • Catches forwards and replies sequencers miss
  • Per-client workspaces with scoped logins
  • Starts at $599 a month
  • Salesforce not native yet
  • AI usage billed on your own model key

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

Master Inbox

$599/mo

Master Inbox prices on client workspaces and mailboxes, with unlimited users on every plan. Listed prices are annual, billed monthly; month to month costs 25% more and annual prepaid saves 15%. For agencies, Agency is $599 a month for 15 client workspaces and 3,000 mailboxes, Scale is $1,297 a month for 40 workspaces and 15,000 mailboxes, and Unlimited is $1,697 a month for unlimited workspaces and 30,000 mailboxes. A Ramp option for agencies with fewer than five clients starts at $299 a month with a $500 onboarding fee that is credited back. For in-house teams, Team is $799 a month for 2,000 mailboxes and Revenue is $1,499 a month for 7,500 mailboxes. Enterprise and the white-label Platform plan start at $2,500 a month on annual terms. The vendor offers a free 7-day proof of concept on your own inboxes. Confirm current terms on the vendor site.

Checked 4 Nov 2026

Common questions

Is Instantly cheaper than Master Inbox?
Instantly starts lower, at $37.60/mo against $599/mo for Master Inbox. 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 Master Inbox for free?
Neither carries a free tier on our listing. Instantly offers a free trial.
Does Instantly or Master Inbox have an MCP server?
Instantly ships a first party MCP server, so an AI assistant can work the product directly.

Not the pair you wanted?

All Instantly alternatives All Master Inbox alternatives Every Outreach tool

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