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Head-to-head · Fax Server Software

Esker VSI-FAX vs Zetafax

  • Updated Oct 2026
  • Both researched from official sources
  • 5 checks side by side
Higher score Esker VSI-FAX #2 in Fax Server Software 9.1/10 Pricing on request · 30-day trial Free trial✓ 4 of 4 features Visit Esker
Zetafax #8 in Fax Server Software 8.3/10 Pricing on request · 30-day trial Free trial✓ 4 of 4 features Visit Equisys

Esker VSI-FAX leads on 0 checks, Zetafax on 0, and 5 are even. Who comes out ahead on the 5 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreEsker VSI-FAX · 9.1/10
  • Free trialboth

Esker VSI-FAX scores higher on our rubric for fax server software: 9.1 against 8.3 out of 10; our editors rank them #2 and #8.

Esker VSI-FAX is the better fit for high-volume enterprise fax operations. Zetafax is the better fit for microsoft-centric on-premise fax teams.

  • Esker VSI-FAX fits best

    High-volume enterprise fax operations

  • Zetafax fits best

    Microsoft-centric on-premise fax teams

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Side by side

Feature Esker VSI-FAX 9.1/10 Visit ↗ Zetafax 8.3/10 Visit ↗
At a glance
Editor score 9.1 8.3
Ranking #2 in Fax Server Software #8 in Fax Server Software
Best for High-volume enterprise fax operations Microsoft-centric on-premise fax teams
Pricing model Paid Paid
Starting price Pricing on request · 30-day trial Pricing on request · 30-day trial
Free plan Not checked yet —
Free trial 30 days 30 days
Free trial length 30 days 30 days
Deployment Self-hosted Self-hosted, Desktop
Platforms Windows, Linux Windows
Support Email, Docs Email, Tickets, Docs
Compliance ISO 27001 GDPR
Integrations 7 integrations 11 integrations
Built for Small business, Mid-market, Enterprise Small business, Mid-market, Enterprise
Features Esker VSI-FAX 4/4 · Zetafax 4/4
Modem or gateway support ✓ ✓
Fax routing rules ✓ ✓
Email fax workflow ✓ ✓
Searchable fax archive ✓ ✓
Specs
Deployment model On_premises On_premises
Concurrent fax channels Not checked yet Not checked yet
Our review
Pros
  • High-volume production faxing with scheduling, batching, and least-cost routing
  • Advanced inbound routing with DNIS, DID, and DTMF support
  • Broad integration options across email, ERP, APIs, SDKs, and Fax over IP
  • Centralizes fax sending, receiving, routing, and archiving
  • Supports Outlook, Exchange Online, SMTP, and Microsoft Office workflows
  • Offers DID, DDI, DTMF, T.38, modem, and fax board support
Cons
  • Product pricing is available through contact with sales
  • On-premises deployment calls for server and fax infrastructure planning
  • Advanced capabilities may require technical administration and integration work
  • Designed for Microsoft Windows deployments
  • Requires on-premises or self-hosted server management
  • No perpetual free plan; licensing is handled through sales
Our verdict

Esker VSI-FAX is server-based fax software for small and large businesses that need to send, receive, route, and archive faxes through enterprise workflows. It supports high-volume production faxing from enterprise applications,…

Read the review →

Zetafax is network fax server software from Equisys for businesses that need centralized fax sending, receiving, routing, archiving, and application integration. It runs on Microsoft Windows and can be installed on physical or virtualized…

Read the review →
  1. Esker VSI-FAXFax Server Software 9.1Pricing on request · 30-day trial
  2. ZetafaxFax Server Software 8.3Pricing on request · 30-day trial

Strengths and trade-offs

  • Esker VSI-FAX — where it wins

    • High-volume production faxing with scheduling, batching, and least-cost routing
    • Advanced inbound routing with DNIS, DID, and DTMF support
    • Broad integration options across email, ERP, APIs, SDKs, and Fax over IP

    Where it doesn't

    • Product pricing is available through contact with sales
    • On-premises deployment calls for server and fax infrastructure planning
    • Advanced capabilities may require technical administration and integration work

  • Zetafax — where it wins

    • Centralizes fax sending, receiving, routing, and archiving
    • Supports Outlook, Exchange Online, SMTP, and Microsoft Office workflows
    • Offers DID, DDI, DTMF, T.38, modem, and fax board support

    Where it doesn't

    • Designed for Microsoft Windows deployments
    • Requires on-premises or self-hosted server management
    • No perpetual free plan; licensing is handled through sales
  • Esker VSI-FAX9.1/10 · Pricing on request · 30-day trial

    A mature on-premises fax server for high-volume workflows and complex routing.

    Visit EskerFull verdict →
  • Zetafax8.3/10 · Pricing on request · 30-day trial

    Centralized fax serving for Microsoft-focused teams with routing, archiving, and automation.

    Visit EquisysFull verdict →

More comparisons

All fax server software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update