QuickFIX vs FIX Orchestra vs FinSpec — what’s the difference?

What’s Going Wrong?

At it’s heart, the problem with FIX connectivity is that it is so old. Really old in fact. As a relic of the mid 90’s, it is older than the commercial internet. Of course, over that time it has blossomed in terms of scope and what it can do, but still the original pioneers would still recognize “modern” FIX today.

  • Documentation is written last (often as an after-thought), and is therefore inaccurate or incomplete, causing client confusion and errors
  • Whilst it is typically the developer who chooses the FIX tags to use, they do not write the docs, and so we play a game of telephone where the documents may not match the code
  • The absence of a mocking capability risks developers burning precious time re-working code because issues are caught too late
  • The absence of automated test case generation means that there is no way of catching documentation errors — they can’t be QA’ed.


QuickFIX XML format

FIX Orchestra

FIX Orchestra format


FinSpec format

Final Thoughts

My purpose in this piece is not to argue the technical functions or benefits of one format or another, as we are far more likely to see multiple formats flourish in the early days before the industry coalesce around one.



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Chris Lees

Chris Lees


Founder @ FixSpec. One man, trying to make a difference.