Model routing APIs
Which API should you route your model calls through?
All four put many models behind one key. They differ less than any of them advertise — and where they do differ, it is not always in our favour.
Side by side
Opens on the 1 row we ran ourselves. Reported rows — what each vendor says about itself — are one click away.
| Enso | OpenRouter | Portkey | LiteLLM | Provenance | |
|---|---|---|---|---|---|
| GPQA-Diamond, run by us | 194 of 198 correct at $25 per million output tokens · 190 at $20 · 184 at $4 [2026-09-11] | not measured by us | not measured by us | not measured by us | we ran this |
GPQA-Diamond, run by us: One set of 198 graduate-level questions through three tiers that differ only in what they are willing to spend. We have not run the other three routers on this set, so their cells say that rather than borrowing a marketing number to sit beside a measurement.
Reading this honestly
A row marked we ran this is a number produced by our own harness, and the link goes to the run. A row marked they published this is each vendor’s own claim, taken from the page linked and dated the day it was read — we relay those, we did not verify them, and they are their numbers and not ours. Where a vendor has not published something the cell says not published rather than being left blank, because a blank reads as zero.
This page is not arranged to make Hanzo look best. Where OpenRouter, Portkey, LiteLLM are ahead, that is on the page. The bet is that a comparison you can check is worth more than one that only says good things about itself.