GMass vs Koncert: Cold Email Platform vs Sales Engagement Platform Comparison
Compare GMass (cold email platform) and Koncert (sales engagement platform) side by side. See pricing, features, and integrations to decide which one, or both, your stack needs.
GMass is a Gmail-based cold email platform starting at $29.95 per month with unlimited emails, contacts, and campaigns, while Koncert is a multi-channel sales engagement platform built around AI dialers and Koncert Cadence, priced through custom sales quotes. GMass fits inbox-based cold email outreach, Koncert fits coordinated calls, email, text, video, and social sequencing, and many teams run both.
Key takeaways
- GMass entry pricing starts at $29.95 per month for the Standard plan with unlimited emails, contacts, and campaigns, subject to Gmail limits.
- GMass Teams plan for 5 users is priced at $175 per month, also with unlimited contacts and emails.
- Koncert uses custom, contact sales pricing across all four listed plans: Melody, Symphony, Melody+, and Symphony+.
- Koncert's Symphony+ AI Parallel Dialer can run 1 to 5 lines, while Symphony runs 1 to 4 lines.
- GMass integrates with Gmail, Google Sheets, Zapier, and Google Workspace, while Koncert integrates with Salesforce, HubSpot, Outreach, SalesLoft, Slack, Gong, and Apollo.io.
Reviewed and updated September 2, 2026
GMass vs Koncert: Cold Email Platform vs Sales Engagement Platform Comparison
GMass is a cold email platform; Koncert is a sales engagement platform. Whether you need one, the other, or both depends on which part of the workflow you are buying for: cold email outreach on one side, multi-channel sales outreach and engagement tracking on the other. This guide lays out what each vendor publishes.
The Quick Answer
GMass is a cold email platform for cold email outreach; Koncert is a sales engagement platform for multi-channel sales outreach and engagement tracking. By each vendor's own wording, GMass lists works inside gmail and unlimited emails, contacts, and campaigns, and Koncert lists koncert cadence multi-channel sequencer across calls, emails, text, video and social and ai parallel dialer running 1 to 5 lines.
GMass publishes an entry price of $29.95/mo; Koncert uses custom pricing, so the two cannot be compared on list price.
If your priority is sending campaigns that land in the inbox and generate replies, GMass is the one built for it; for coordinating outreach across email, phone, and social channels, that is Koncert. Many teams run one of each.
Understanding the Core Difference
GMass is Gmail-based mass email and mail merge platform with unlimited emails, campaigns, and contacts directly inside Gmail.
Koncert is Multi-channel sales engagement platform built around five sales dialers plus Koncert Cadence, a sequencer that runs phone, email, video, text and social touchpoints with bi-directional CRM sync.
The two platforms take different approaches to solving the same core challenge.
Pricing Comparison
Standard
Melody (AI Flow Dialer)
GMass Pricing (as of September 2026)
| Plan | Price | Contacts | Emails |
|---|---|---|---|
| Standard | $29.95/mo | Unlimited | Unlimited (Gmail limits apply) |
| Premium | $39.95/mo | Unlimited | Unlimited (Gmail limits apply) |
| Professional | $59.95/mo | Unlimited | Unlimited (Gmail limits apply) |
| Teams (5 users) | $175/mo | Unlimited | Unlimited (Gmail limits apply) |
Source: GMass Pricing
Koncert Pricing (as of September 2026)
| Plan | Price | Contacts |
|---|---|---|
| Melody (AI Flow Dialer) | Contact Sales | Single-Line Power Dialer |
| Symphony (AI Parallel Dialer) | Contact Sales | 1 to 4 lines |
| Melody+ (AI Flow Dialer) | Contact Sales | Single-Line Power Dialer |
| Symphony+ (AI Parallel Dialer) | Contact Sales | 1 to 5 lines |
Source: Koncert Pricing
Pricing Analysis
One or both platforms use custom or contact-based pricing for some tiers. Reach out to their sales teams for exact quotes based on your usage needs.
Features Breakdown
- Works inside Gmail
- Unlimited emails, contacts, and campaigns
- Mail merge personalization
- Free email verification
- Automated follow-up sequences
- A/B testing
- and 4 more listed below
- Koncert Cadence multi-channel sequencer across calls, emails, text, video and social
- AI Parallel Dialer running 1 to 5 lines
- AI Flow Dialer single-line power dialer
- Remote Coach for live and recorded call listening
- Whisper Mode for live coaching during a call
- Fully managed Caller ID reputation with a heat map
- and 4 more listed below
GMass Key Features
- Works inside Gmail
- Unlimited emails, contacts, and campaigns
- Mail merge personalization
- Free email verification
- Automated follow-up sequences
- A/B testing
- Spam Solver deliverability tool
- Custom tracking links
- Inbox rotation
- API and Zapier access
Koncert Key Features
- Koncert Cadence multi-channel sequencer across calls, emails, text, video and social
- AI Parallel Dialer running 1 to 5 lines
- AI Flow Dialer single-line power dialer
- Remote Coach for live and recorded call listening
- Whisper Mode for live coaching during a call
- Fully managed Caller ID reputation with a heat map
- Automated local presence caller IDs
- Voicemail sequencing and voicemail drop
- AI objection detection with AI summary notes and transcriptions
- DataGenie waterfall data enrichment
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 GMass
- Works inside Gmail
- Unlimited emails, contacts, and campaigns
- Mail merge personalization
- Free email verification
- Automated follow-up sequences
- A/B testing
- Spam Solver deliverability tool
- Custom tracking links
- Inbox rotation
- API and Zapier access
Listed only by Koncert
- Koncert Cadence multi-channel sequencer across calls, emails, text, video and social
- AI Parallel Dialer running 1 to 5 lines
- AI Flow Dialer single-line power dialer
- Remote Coach for live and recorded call listening
- Whisper Mode for live coaching during a call
- Fully managed Caller ID reputation with a heat map
- Automated local presence caller IDs
- Voicemail sequencing and voicemail drop
- AI objection detection with AI summary notes and transcriptions
- DataGenie waterfall data enrichment
Integration Ecosystem
GMass Integrations
GMass connects with: Gmail, Google Sheets, Zapier, Google Workspace.
Koncert Integrations
Koncert connects with: Salesforce, HubSpot, Outreach, SalesLoft, Slack, Gong, Apollo.io.
Integrations listed only by GMass: Gmail, Google Sheets, Zapier, Google Workspace.
Integrations listed only by Koncert: Salesforce, HubSpot, Outreach, SalesLoft, Slack, Gong, Apollo.io.
Use Case Recommendations
Best Fit for GMass
- Budget-conscious teams looking for an affordable cold email platform
- Sales teams running high-volume outbound email campaigns
- Agencies managing multiple client outreach programs
- SDR teams focused on pipeline generation
Best Fit for Koncert
- Organizations with complex tech stacks needing broad integration support (7 integrations)
- Enterprise buyers who prefer custom pricing and dedicated support
- SDR teams running multi-channel outreach sequences
- Sales managers tracking team engagement metrics
Feature Comparison Summary
| Feature | GMass | Koncert |
|---|---|---|
| Starting Price | $29.95/mo | Contact Sales |
| Top Tier Price | $175/mo | Contact Sales |
| Total Features Listed | 10 | 10 |
| Integrations | 4 | 7 |
| Founded | 2015 | N/A |
Getting Started Checklist
- Define your cold email outreach and multi-channel sales outreach and engagement tracking requirements and monthly budget
- Estimate your expected email sending volume and sequences and engagement actions 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
GMass serves the cold email outreach side of an outbound stack and Koncert the multi-channel sales outreach and engagement tracking side. GMass publishes an entry price of $29.95/mo, while Koncert uses custom pricing for its plans, so compare on features and on the quote you receive. 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 GMass and Koncert for current information.
Frequently asked questions.
Frequently asked questions- What is the main difference between GMass and Koncert?
- GMass is a Gmail-based cold email platform focused on mass email and mail merge campaigns, while Koncert is a multi-channel sales engagement platform built around five sales dialers plus Koncert Cadence, a sequencer covering phone, email, video, text, and social touchpoints with bi-directional CRM sync.
- How much does GMass cost compared to Koncert?
- GMass publishes clear pricing starting at $29.95 per month for its Standard plan, rising to $59.95 per month for Professional and $175 per month for a 5 user Teams plan. Koncert does not publish prices and instead uses custom, contact sales pricing across all its dialer plans, so the two cannot be compared on list price.
- Can GMass and Koncert be used together?
- Yes, the article notes that many teams run one of each because they solve different parts of the outreach workflow. GMass handles cold email campaigns inside Gmail, while Koncert coordinates multi-channel outreach across calls, email, text, video, and social with CRM sync.
- What integrations does each platform support?
- GMass connects with Gmail, Google Sheets, Zapier, and Google Workspace. Koncert connects with Salesforce, HubSpot, Outreach, SalesLoft, Slack, Gong, and Apollo.io, reflecting its focus on sales engagement workflows tied to CRM and sales tool ecosystems.
- Which tool is better for cold email outreach, GMass or Koncert?
- GMass is the tool built specifically for cold email outreach, offering unlimited emails, contacts, and campaigns directly inside Gmail along with mail merge, A/B testing, and deliverability features. Koncert is positioned instead for multi-channel sales engagement across calls, email, text, video, and social rather than dedicated cold email sending.
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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