Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.5
91
Mistral Medium 3.5 128B
79
Verified leaderboard positions: GPT-5.5 #5 · Mistral Medium 3.5 128B unranked
Pick GPT-5.5 if you want the stronger benchmark profile. Mistral Medium 3.5 128B only becomes the better choice if coding is the priority or you want the cheaper token bill.
Coding
+19.0 difference
GPT-5.5
Mistral Medium 3.5 128B
$5 / $30
$1.5 / $7.5
N/A
N/A
N/A
N/A
1M
256K
Pick GPT-5.5 if you want the stronger benchmark profile. Mistral Medium 3.5 128B only becomes the better choice if coding is the priority or you want the cheaper token bill.
GPT-5.5 is clearly ahead on the provisional aggregate, 91 to 79. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $1.50 input / $7.50 output per 1M tokens for Mistral Medium 3.5 128B. That is roughly 4.0x on output cost alone. GPT-5.5 gives you the larger context window at 1M, compared with 256K for Mistral Medium 3.5 128B.
GPT-5.5 is ahead on BenchLM's provisional leaderboard, 91 to 79.
Mistral Medium 3.5 128B has the edge for coding in this comparison, averaging 77.6 versus 58.6. Inside this category, Terminal-Bench Hard is the benchmark that creates the most daylight between them.
For engineers, researchers, and the plain curious — a weekly brief on new models, ranking shifts, and pricing changes.
Free. No spam. Unsubscribe anytime.