Model comparison

GPT-5.5 vs Xiaomi MiMo-V2.6-Pro

OpenAI against Xiaomi, compared on context, price, and verified benchmark results.

Catalog record checked September 26, 2026Individual provider fields may changeEvidence confidence: High — see receipts below

OpenAI

GPT-5.5

Frontier

Xiaomi

Xiaomi MiMo-V2.6-Pro

Frontier · Open weights

AI model capability comparison
Specification	GPT-5.5	Xiaomi MiMo-V2.6-Pro
Provider
Provider	OpenAI	Xiaomi
Tier
Tier	Frontier	Frontier
Context window
Context window	Winner: 1.05M	1.05M
Max output
Max output	128K	Not verifiedUnverified
Input / 1M tokens
Input / 1M tokens	$5	Winner: $0.435
Output / 1M tokens
Output / 1M tokens	$30	Winner: $0.87
Weights
Weights	Closed	Open
Parameters
Parameters	Not disclosedUnverified	1.02T total / 42B active (MoE)
Reasoning levels
Reasoning levels	none, low, medium, high, xhigh	Not verifiedUnverified
Modalities
Modalities	text, image	text, image, video, audio
License
License	Not disclosedUnverified	MIT
API model id
API model id	gpt-5.5	mimo-v2.6-pro
Released
Released	April 23, 2026	September 21, 2026
Artificial Analysis Intelligence Index [xhigh] (2026-09-26)
Artificial Analysis Intelligence Index [xhigh] (2026-09-26)	38.4	Not verifiedUnverified
Artificial Analysis Intelligence Index (2026-09-26)
Artificial Analysis Intelligence Index (2026-09-26)	Not verifiedUnverified	46.3
SWE-bench Verified (2026-09-01)
SWE-bench Verified (2026-09-01)	82.6	Not verifiedUnverified
Terminal-Bench 2.1 (2026-07-27)
Terminal-Bench 2.1 (2026-07-27)	83.4	Winner: 89.9
GPQA Diamond (2026-07-27)
GPQA Diamond (2026-07-27)	93.5	Not verifiedUnverified
Humanity's Last Exam (2026-04-23)
Humanity's Last Exam (2026-04-23)	52.2	Not verifiedUnverified
DeepSWE 1.1 (2026-09-21)
DeepSWE 1.1 (2026-09-21)	Not verifiedUnverified	71.9

Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.

Benchmark receipts

Where each score comes from, and how far it can be compared across models.

2026-09-26
Artificial Analysis
Composite index blending reasoning, knowledge, and coding evals into one 0–100 score.
Comparable with caveatOnly same-version scores are comparable. v4.3.2 was rebaselined (the top score fell from 66 on v4.1.1 to ~58), so v4.1.1 figures must not be compared with v4.3.2 figures — check measuredAt.
2026-09-21
Xiaomi MiMo-V2.6 announcement (vendor)
Agentic software engineering: pass@1 on real repo tasks with reported cost per completed task.
Directly comparable
2026-09-01
vals.ai SWE-bench Verified leaderboard (independent, mini-swe-agent bash-only); official SWE-bench not published
Real GitHub issue resolution: does the model's patch pass the hidden tests.
Comparable with caveatPost-audit vendor claims and pre-audit scores sit on different task trust levels; scaffolding (agent harness, compute budget) also dominates results. Never aggregate across scaffolds.
2026-07-27
Kimi K3 model card (vendor-reported, xhigh); announcement charts show 93.6 — minor conflict preserved
Agentic terminal work: multi-step tasks executed in a sandboxed shell environment.
Comparable with caveatNot comparable with Terminal-Bench 3.0 or 4.0 (different task sets) or v1; harness configuration (container, time limits) also shifts results.
2026-04-23
OpenAI — Introducing GPT-5.5 (vendor, with tools; 41.4 no tools)
Frontier-knowledge ceiling: extremely hard multi-domain questions written to be near-impossible without deep expertise.
Comparable with caveatSubset/tool configurations (text-only vs with-tools) differ between vendors and materially change scores; must match configuration to compare.

Pricing tiers

GPT-5.5: Standard $5/$30 per MTok; >272K input billed 2x in / 1.5x out. Cached input $0.50/MTok; batch $2.50/$15.

Xiaomi MiMo-V2.6-Pro: $0.435/$0.87 per MTok (cache hit $0.0036; cache writes free for a limited time) — unchanged from V2.5-Pro. UltraSpeed mode (mimo-v2.6-pro-ultraspeed) costs $4.35/$8.70. Open weights (MIT) as MiMo-V2.6-Pro-RL.

FrontierRecord checked September 26, 2026

GPT-5.5

GPT-5.5 is OpenAI's April 2026 flagship, now two generations back — strong on Terminal-Bench 2.0 (82.7%) with a 1.05M-token context.

Best for

Reasoning
Agentic coding
Long-context work

Watch out

Superseded by GPT-5.6 and then GPT-6 Astra/Sol; still served and widely integrated.

FrontierOpen weightsRecord checked September 26, 2026

Xiaomi MiMo-V2.6-Pro

MiMo-V2.6-Pro is Xiaomi's open-weight (MIT) 1.02T MoE with omni-modal input and a 1M context — the top open-weight model on the Artificial Analysis index at under $1 per million output tokens.

Best for

Open-weight frontier work
Omni-modal input
Cheap long-context API

Watch out

Max output is not verified; vendor benchmark claims (DeepSWE 71.9) are not yet independently reproduced.

When the cheaper one wins

Xiaomi MiMo-V2.6-Pro is cheaper on output at $0.87 per million tokens against $30 for GPT-5.5 — about 34×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. These are standard-tier API rates, excluding batch and cache discounts.

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Evidence confidence: High

How strong and complete the evidence behind this comparison is — not a prediction of which model is better.

Pricing verified on both sides — Input and output rates are verified for both models.
2/5 core specs verified on both sides — Not published for at least one side: max output, parameter count, reasoning levels.
2 shared named benchmarks with differing scores — Measured on: Artificial Analysis Intelligence Index, Terminal-Bench 2.1.
Verified within the last 90 days — Newest catalog check was 2 days ago.
Both models carry source citations — Each side has at least two catalog sources on record.

Source receipts

Each catalog figure was checked against the provider or an independent second source on the date shown.

GPT-5.5: OpenAI — Introducing GPT-5.5 (accessed 2026-08-29)
GPT-5.5: OpenAI API pricing (gpt-5.5 $5/$30) (accessed 2026-08-29)
Xiaomi MiMo-V2.6-Pro: Xiaomi — MiMo-V2.6 (pricing, benchmarks) (accessed 2026-09-26)
Xiaomi MiMo-V2.6-Pro: Hugging Face — XiaomiMiMo/MiMo-V2.6-Pro-RL (MIT, 1.02T/42B, 1M) (accessed 2026-09-26)

Related comparisons

Diving deeper on one model? GPT-5.5 · Xiaomi MiMo-V2.6-Pro

Common questions

GPT-5.5 vs Xiaomi MiMo-V2.6-Pro

Answered from the verified figures on this page rather than general guidance.

Is GPT-5.5 or Xiaomi MiMo-V2.6-Pro cheaper for input?

Xiaomi MiMo-V2.6-Pro is cheaper at $0.435 per million input tokens, against $5 for GPT-5.5 — roughly 11× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; GPT-5.5 has tiered pricing: Standard $5/$30 per MTok; >272K input billed 2x in / 1.5x out. Cached input $0.50/MTok; batch $2.50/$15. Xiaomi MiMo-V2.6-Pro has tiered pricing: $0.435/$0.87 per MTok (cache hit $0.0036; cache writes free for a limited time) — unchanged from V2.5-Pro. UltraSpeed mode (mimo-v2.6-pro-ultraspeed) costs $4.35/$8.70. Open weights (MIT) as MiMo-V2.6-Pro-RL.

Is GPT-5.5 or Xiaomi MiMo-V2.6-Pro cheaper for output?

Xiaomi MiMo-V2.6-Pro is cheaper at $0.87 per million output tokens, against $30 for GPT-5.5 — roughly 34× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; GPT-5.5 has tiered pricing: Standard $5/$30 per MTok; >272K input billed 2x in / 1.5x out. Cached input $0.50/MTok; batch $2.50/$15. Xiaomi MiMo-V2.6-Pro has tiered pricing: $0.435/$0.87 per MTok (cache hit $0.0036; cache writes free for a limited time) — unchanged from V2.5-Pro. UltraSpeed mode (mimo-v2.6-pro-ultraspeed) costs $4.35/$8.70. Open weights (MIT) as MiMo-V2.6-Pro-RL.

Which has the larger context window, GPT-5.5 or Xiaomi MiMo-V2.6-Pro?

Both accept about 1.05M tokens of context, so document length will not decide between them.

Should I use GPT-5.5 or Xiaomi MiMo-V2.6-Pro?

Both sit in the frontier tier, so the choice usually comes down to price and context rather than capability. GPT-5.5 suits reasoning; Xiaomi MiMo-V2.6-Pro suits open-weight frontier work.

Can I self-host GPT-5.5 or Xiaomi MiMo-V2.6-Pro?

Xiaomi MiMo-V2.6-Pro publishes open weights, but self-hosting and third-party provider access depend on the licence, hardware, serving support, and availability. GPT-5.5 is a closed model whose supported access paths are controlled by its provider.

Next step

Choosing between them

The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.

Input price: Xiaomi MiMo-V2.6-Pro costs $0.435 per 1M tokens versus $5 for GPT-5.5 — a 11.5x difference at the headline tier.
Context: GPT-5.5 takes 1.05M against 1.05M for Xiaomi MiMo-V2.6-Pro — only decisive if your prompts approach the smaller window.
Measured capability: Xiaomi MiMo-V2.6-Pro leads Artificial Analysis Intelligence Index 46.3 to 38.4 (measured 2026-09-26).
Deployment: Xiaomi MiMo-V2.6-Pro publishes weights you can self-host; the other is API-only.

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