Boost Inbox vs Instantly: Email Warmup Tool vs Cold Email Platform Comparison
Compare Boost Inbox (email warmup tool) and Instantly (cold email platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
Boost Inbox is an email warmup tool focused on domain warming and deliverability, starting at $5/mo, while Instantly is a cold email platform for outreach campaigns, starting at $47/mo. They solve different parts of the workflow, so many teams use both rather than choosing one over the other.
Key takeaways
- Boost Inbox's entry plan costs $5/mo and includes 1 mailbox for warmup with 50 daily positive engagements.
- Instantly's entry plan, Growth, costs $47/mo and includes 1000 uploaded contacts with 5000 emails monthly.
- Instantly offers 4 pricing tiers (Growth, Hypergrowth, Light Speed, Enterprise) compared to Boost Inbox's 3 tiers (Starter, Team, Premium).
- Boost Inbox integrates with Gmail, GSuite, Outlook 365, Yahoo Mail, Amazon SES, and SMTP, while Instantly integrates with 9 tools including HubSpot, Salesforce, Pipedrive, Zapier, and Slack.
- Instantly's top tier, Light Speed, costs $358/mo and supports 100,000 uploaded contacts with 500,000 emails monthly.
Reviewed and updated September 2, 2026
Boost Inbox vs Instantly: Email Warmup Tool vs Cold Email Platform Comparison
Boost Inbox is an email warmup tool; Instantly is a cold email platform. Whether you need one, the other, or both depends on which part of the workflow you are buying for: email domain warming and deliverability on one side, cold email outreach on the other. This guide lays out what each vendor publishes.
The Quick Answer
Boost Inbox is an email warmup tool for email domain warming and deliverability; Instantly is a cold email platform for cold email outreach. By each vendor's own wording, Boost Inbox lists email warmup and fully automated, and Instantly lists unlimited email accounts and unlimited email warmup.
Boost Inbox offers a lower entry point at $5/mo compared to Instantly at $47/mo.
If your priority is building sender reputation and improving inbox placement, Boost Inbox is the one built for it; for sending campaigns that land in the inbox and generate replies, that is Instantly. Many teams run one of each.
Understanding the Core Difference
Boost Inbox is Email warmup service that gradually increases sending activity to build trust with email providers. It sends realistic emails from your inbox on a daily basis, keeps them out of spam, opens and bookmarks them, and replies to a portion of them to generate positive interactions.
Instantly is Cold email platform with unlimited email accounts, unlimited warmup, and a 450M+ B2B lead database.
The two platforms take different approaches to solving the same core challenge.
Pricing Comparison
Starter
Growth
Boost Inbox Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Starter | $5/mo | 1 Mailbox For Warmup | 50 Daily Positive Engagement |
| Team | $9/mo | 3 Mailboxes For Warmup | 50 Daily Positive Engagement per mailbox |
| Premium | $19/mo | 8 Mailboxes For Warmup | 50 Daily Positive Engagement per mailbox |
Source: Boost Inbox Pricing
Instantly Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Growth | $47/mo | 1000 Uploaded Contacts | 5000 Emails Monthly |
| Hypergrowth | $97/mo | 25 000 Uploaded Contacts | 125,000 emails/month |
| Light Speed | $358/mo | 100 000 Uploaded Contacts | 500 000 Emails Monthly |
| Enterprise | Contact Sales | 100 000+ Uploaded Contacts | 500 000+ Emails Monthly |
Source: Instantly Pricing
Pricing Analysis
Boost Inbox is more affordable at the entry level ($5/mo vs $47/mo). For teams with tight budgets or those just getting started with email domain warming and deliverability and cold email outreach, this price difference matters.
Instantly offers 4 pricing tiers compared to Boost Inbox's 3, giving you more granularity as you scale.
Features Breakdown
- Email Warmup
- Fully Automated
- Status Reports
- Human Review
- Premium Support
- Realistic emails sent from your inbox daily
- and 2 more listed below
- Unlimited email accounts
- Unlimited email warmup
- Email verification
- Master inbox
- Campaign analytics
- A/B testing
- and 2 more listed below
Boost Inbox Key Features
- Email Warmup
- Fully Automated
- Status Reports
- Human Review
- Premium Support
- Realistic emails sent from your inbox daily
- Email health checker tool
- Inbox reputation analytics
Instantly Key Features
- Unlimited email accounts
- Unlimited email warmup
- Email verification
- Master inbox
- Campaign analytics
- A/B testing
- AI-powered features
- Dedicated IP rotation (Light Speed+)
The two lists below are a diff of each vendor's own feature list by exact wording, so a capability both tools offer can appear on either side under a different name.
Listed only by Boost Inbox
- Email Warmup
- Fully Automated
- Status Reports
- Human Review
- Premium Support
- Realistic emails sent from your inbox daily
- Email health checker tool
- Inbox reputation analytics
Listed only by Instantly
- Unlimited email accounts
- Unlimited email warmup
- Email verification
- Master inbox
- Campaign analytics
- A/B testing
- AI-powered features
- Dedicated IP rotation (Light Speed+)
Integration Ecosystem
Boost Inbox Integrations
Boost Inbox connects with: Gmail, GSuite, Outlook 365, Yahoo Mail, Amazon SES, SMTP.
Instantly Integrations
Instantly connects with: HubSpot, Salesforce, Pipedrive, Zapier, Make, n8n, Clay, Slack, Google Calendar.
Integrations listed only by Boost Inbox: Gmail, GSuite, Outlook 365, Yahoo Mail, Amazon SES, SMTP.
Integrations listed only by Instantly: HubSpot, Salesforce, Pipedrive, Zapier, Make, n8n, Clay, Slack, Google Calendar.
Use Case Recommendations
Best Fit for Boost Inbox
- Budget-conscious teams looking for an affordable email warmup tool
- Teams launching new email domains for outreach
- Organizations recovering from deliverability issues
- Agencies managing warmup across multiple client domains
Best Fit for Instantly
- Budget-conscious teams looking for an affordable cold email platform
- Organizations with complex tech stacks needing broad integration support (9 integrations)
- Enterprise buyers who prefer custom pricing and dedicated support
Feature Comparison Summary
| Feature | Boost Inbox | Instantly |
|---|---|---|
| Starting Price | $5/mo | $47/mo |
| Top Tier Price | $19/mo | Contact Sales |
| Total Features Listed | 8 | 8 |
| Integrations | 6 | 9 |
Getting Started Checklist
- Define your email domain warming and deliverability and cold email outreach requirements and monthly budget
- Estimate your expected warmup email volume and email sending volume to find the right tier
- List the integrations your team currently relies on
- Sign up for free trials or demos of both platforms
- Run a small test with each tool before making a commitment
- Evaluate the onboarding experience and support quality
Final Thoughts
Boost Inbox serves the email domain warming and deliverability side of an outbound stack and Instantly the cold email outreach side. Boost Inbox offers a more accessible entry point at $5/mo, while Instantly starts at $47/mo. Your decision should weigh pricing against the specific features that matter most for your workflow.
Start with a trial of each to see which platform fits your team's daily process. The best tool is the one your team actually uses consistently.
Pricing and features verified as of September 2026. Visit Boost Inbox and Instantly for current information.
Frequently asked questions.
Frequently asked questions- What is the difference between Boost Inbox and Instantly?
- Boost Inbox is an email warmup tool that focuses on email domain warming and deliverability, sending realistic emails daily to build sender reputation. Instantly is a cold email platform built for sending outreach campaigns, with unlimited email accounts, unlimited warmup, and a 450M+ B2B lead database. They address different parts of the same workflow.
- How much does Boost Inbox cost compared to Instantly?
- Boost Inbox starts at $5/mo for its Starter plan with 1 mailbox for warmup, while Instantly starts at $47/mo for its Growth plan with 1000 uploaded contacts and 5000 emails monthly. Boost Inbox's top tier, Premium, is $19/mo, while Instantly's Light Speed tier runs $358/mo before Enterprise custom pricing.
- Do I need both Boost Inbox and Instantly?
- Many teams run both since they serve different purposes. Boost Inbox handles email domain warming and deliverability, while Instantly handles cold email outreach and campaign sending. If your priority is inbox placement and sender reputation, Boost Inbox fits, and for sending campaigns that generate replies, Instantly is the platform built for that.
- What integrations does each platform support?
- Boost Inbox connects with Gmail, GSuite, Outlook 365, Yahoo Mail, Amazon SES, and SMTP. Instantly connects with HubSpot, Salesforce, Pipedrive, Zapier, Make, n8n, Clay, Slack, and Google Calendar, giving it broader support for teams with complex tech stacks.
- Which tool is better for a budget-conscious team just starting out?
- Boost Inbox is the more affordable option at the entry level, priced at $5/mo compared to Instantly's $47/mo. Boost Inbox is recommended for budget-conscious teams launching new email domains or recovering from deliverability issues, while Instantly is recommended for budget-conscious teams specifically needing an affordable cold email platform.
About the author.
Tim Carden is CMO / CTO at RevenueFlow, which builds and operates outbound revenue engines for B2B companies. Studied at McGill University.
Tim Carden · CMO / CTO
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