Suggestions appear as you type. Use the up and down arrows to choose one and Enter to open it.

This page's audience real numbers from our own analytics — open to see them
–Visitors
–Page views
–Clicks to vendors
–Time on page
–Reading now
Clicks to vendors, by tool
  • –
Top countries
  • –
Devices
  • –

– · counted by iTechGuides's own first-party analytics, bots removed, every figure rounded down · how we count

Head-to-head · Enterprise Service Bus Software

Mule ESB vs OpenCelium

  • Updated Oct 2026
  • Both researched from official sources
  • 3 checks side by side
Higher score Mule ESB #2 in Enterprise Service Bus Software 9.1/10 From $2,000/mo (annual) · 30-day trial ✓ 0 of 4 features Visit MuleSoft
OpenCelium #11 in Enterprise Service Bus Software 7.4/10 Free plan Free plan✓ 2 of 4 features Visit OpenCelium

Mule ESB leads on 0 checks, OpenCelium on 3, and 0 are even. Who comes out ahead on the 3 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreMule ESB · 9.1/10
  • Free planonly OpenCelium
  • Most featuresOpenCelium · 2 of 4

Mule ESB scores higher on our rubric for enterprise service bus software: 9.1 against 7.4 out of 10; our editors rank them #2 and #11.

OpenCelium offers free plan; Mule ESB doesn't. OpenCelium offers message transformation; Mule ESB doesn't publish it. OpenCelium offers visual flow designer; Mule ESB doesn't publish it.

Mule ESB is the better fit for enterprises needing managed, hybrid integration. OpenCelium is the better fit for small teams automating API integrations on a budget.

  • Mule ESB fits best

    Enterprises needing managed, hybrid integration

  • OpenCelium fits best

    Small teams automating API integrations on a budget

Advertiser disclosure: iTechGuides is reader-supported. We may earn a commission when you click some links. How we rank.

Side by side

Feature Mule ESB 9.1/10 Visit ↗ OpenCelium 7.4/10 Visit ↗
At a glance
Editor score 9.1 7.4
Ranking #2 in Enterprise Service Bus Software #11 in Enterprise Service Bus Software
Best for Enterprises needing managed, hybrid integration Small teams automating API integrations on a budget
Pricing model Paid Free
Starting price $2,000/mo Not published
Free plan — ✓ (best)
Free trial — —
Deployment Cloud, Self-hosted Self-hosted, Cloud
Platforms Web Web
Support Docs Email
Built for Small business, Mid-market, Enterprise Small business, Mid-market, Enterprise
Features Mule ESB 0/4 · OpenCelium 2/4
Message transformation Not published ✓ (best)
Queue integration Not published Not published
High availability Not published Not published
Visual flow designer Not published ✓ (best)
Specs
Deployment model Not published On-premises
Protocol support Not published HTTP, JSON-RPC; documentation also references SOAP
Our review
Pros
  • Routes and orchestrates integration flows with DataWeave transformations.
  • Supports cloud, hybrid, Runtime Fabric, and on-premises deployments.
  • Offers reusable and custom connectors, plus API gateway policy controls.
  • Visual multi-step workflows support branching, loops, and data mapping.
  • Run workflows manually, on a schedule, or from a webhook.
  • The Open plan includes all connectors and 25,000 API Ops/month.
Cons
  • The published starting price is $2,000/month with annual billing.
  • There is no free plan; the free trial lasts 30 days.
  • Current package pricing is not a standalone Mule ESB license.
  • Its focus is API workflows rather than a traditional message-queue bus.
  • The Open plan is capped at 25,000 API Ops/month.
  • Paid plans add allowances and support, but prices are not stated here.
Our verdict

Mule ESB, now documented as Mule runtime engine, is an integration runtime for connecting applications, services, APIs, databases, and devices. It is aimed at organizations that need to route messages and transform data across cloud and…

Read the review →

OpenCelium connects applications through their APIs using visual workflows. Teams define connectors and API calls, arrange execution order, and add branching, loops, field mapping, and transformations. Workflows can run manually, on a…

Read the review →
  1. Mule ESBEnterprise Service Bus Software 9.1From $2,000/mo (annual) · 30-day trial
  2. OpenCeliumEnterprise Service Bus Software 7.4Free plan

Strengths and trade-offs

  • Mule ESB — where it wins

    • Routes and orchestrates integration flows with DataWeave transformations.
    • Supports cloud, hybrid, Runtime Fabric, and on-premises deployments.
    • Offers reusable and custom connectors, plus API gateway policy controls.

    Where it doesn't

    • The published starting price is $2,000/month with annual billing.
    • There is no free plan; the free trial lasts 30 days.
    • Current package pricing is not a standalone Mule ESB license.

  • OpenCelium — where it wins

    • Visual multi-step workflows support branching, loops, and data mapping.
    • Run workflows manually, on a schedule, or from a webhook.
    • The Open plan includes all connectors and 25,000 API Ops/month.

    Where it doesn't

    • Its focus is API workflows rather than a traditional message-queue bus.
    • The Open plan is capped at 25,000 API Ops/month.
    • Paid plans add allowances and support, but prices are not stated here.
  • Mule ESB9.1/10 · From $2,000/mo (annual) · 30-day trial

    A flexible integration runtime for hybrid estates, with a substantial annual starting price.

    Visit MuleSoftFull verdict →
  • OpenCelium7.4/10 · Free plan

    An open-source API workflow platform for teams that need visual integrations on a budget.

    Visit OpenCeliumFull verdict →

More comparisons

All enterprise service bus software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update