FIX Protocol Testing Making FIX Protocol testing accessible and affordable

Whether you are building your own trading sytem or using a vendor solution, reliable testing of FIX message conformance is crucial to success. FIXSIM was developed to offer a modern soltuion to FIX testing. Simply by connecting your FIX engine securely through the Internet, FIXSIM provides you with both manual and automated testing solutions with no software to download.

Manual Testing

With our web based portal, easily configure and montior FIX message traffic. See orders and execution messages and control how orders are executed.

Message Views

See direct FIX message traffic and view messages in raw FIX format as well as translated tag numbers and values.

Blotter Views

Our trade blotter views provide you with a trader's viewpoint on active orders. See order quantities, avergae prices, and execution values. Take action on orders in the blotter with actions like: Partially fill, cancel, correct prices, and more right from the web portal.

Automated Testing

Having an automated solution to FIX testing provides assurance you maintain compliance with FIX integrations. Build, design, and fun repeatable FIX test cases with FIXSIM.

Rule Builder

Use our web portal to build rules and actions to respond to messages. For example, if an order is received in FIXSIM for IBM, acknowledge the order, partial fill, and cancel the remaining quantity. Configure your FIXSIM sessions to your testing scripts to provider user free automation.


We offer our Web API to directly control FIXSIM via ReSTful calls (e.g. Curl). Using Swagger/OpenAPI, our API is fully documented and can easily generate a client in any language (C#, Java, Ruby, more). This provides you with the full power of FIXSIM to be controlled by your application.

Customer Recommendations Join the hundreds of customers who use FIXSIM. We're also our own customer!

"We started with our UK QA team, now rolled out to global teams!"

Quality Assurance Lead / Fintech Vendor

"Essential to help us stress test clients accessing our Dark Pool"

CEO / US Equity Exchange

"As a contractor, I use FIXSIM for helping build FIX solutions for my clients."

FIX Protocol Client Testing

99.9% Uptime Web Based Fully Responsive Monthly Subscriptions