Model vs model

GPT-5.5 vs A.X-K2

A debate-ready pair page: current winner, strongest alternative, decisive benchmarks, and the warning that should travel with the claim.

Use case · Everyday chatbot
Winner · GPT-5.5
Sources · All public sources

Winner

GPT-5.5

OpenAI

8benchmarks won

Professional reasoning
Chat / text

Versus · Everyday chatbot

GPT-5.5 leads this compare set for everyday chatbot.

GPT-5.58 of 8 wins

Verified and stable

0 shared benchmarks are still too close to call, so the win stays conditional. This compare uses all public sources, with provider-official evidence labeled separately.

Close calls: 0
Sources: All public

Full compare workspace Disagreement page

100%win share

Challenger

A.X-K2

Unknown

0benchmarks won

Chat / text
Reasoning / math / science

The cases in full

GPT-5.5 case

Professional reasoning
Chat / text

A.X-K2 case

Chat / text
Reasoning / math / science

What changes the outcome

GPT-5.5: 38 visible benchmark gaps still leave room for the result to move.
A.X-K2: 124 visible benchmark gaps still leave room for the result to move.

Why this result is surprising

The visible shared evidence is more decisive than usual for this compare set.
Very few shared benchmarks are decisively separating these models.

Why this is not a clean win

0 shared benchmarks are still too close to call, so the win stays conditional. This compare uses all public sources, with provider-official evidence labeled separately.
A.X-K2 remains the strongest alternative once you change use case, mode, or missing-evidence assumptions.

Open full compare workspace Open evidence page Open disagreement page

Decisive benchmarks

8 of 132 benchmarks


Intelligence Index AA · index Text · Chat / text	2376% exact aliasverified runtime Row details Raw value 23 Percentile 76% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	23n/a exact aliasverified runtimeContext only Row details Raw value 23 Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
GPQA AA · % Text · Reasoning / math / science	76.8%67.7% exact aliasverified runtime Row details Raw value 76.8% Percentile 67.7% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	85.7%n/a exact aliasverified runtimeContext only Row details Raw value 85.7% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
Humanity's Last Exam AA · % Text · Reasoning / math / science	13.7%65.2% exact aliasverified runtime Row details Raw value 13.7% Percentile 65.2% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	29.6%n/a exact aliasverified runtimeContext only Row details Raw value 29.6% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
CritPt AA · % Text · Reasoning / math / science	1.4%69.7% exact aliasverified runtime Row details Raw value 1.4% Percentile 69.7% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	8.9%n/a exact aliasverified runtimeContext only Row details Raw value 8.9% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
SciCode AA · % Code · Coding	54.5%76.8% exact aliasverified runtime Row details Raw value 54.5% Percentile 76.8% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Medium) Source row	41%n/a exact aliasverified runtimeContext only Row details Raw value 41% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
AA-Omniscience accuracy AA · % Text · Chat / text	45.6%86.5% exact aliasverified runtime Row details Raw value 45.6% Percentile 86.5% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	18.6%n/a exact aliasverified runtimeContext only Row details Raw value 18.6% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
AA-Omniscience non-hallucination AA · % Text · Chat / text	7.3%16.4% exact aliasverified runtime Row details Raw value 7.3% Percentile 16.4% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	67%n/a exact aliasverified runtimeContext only Row details Raw value 67% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a
Long Context Reasoning AA · % Document · Long context	64%61.5% exact aliasverified runtime Row details Raw value 64% Percentile 61.5% Last updated recent Eligibility headline eligible Identity provider alias (0.94) Source label GPT-5.5 (Non-reasoning) Source row	70%n/a exact aliasverified runtimeContext only Row details Raw value 70% Percentile n/a Last updated recent Eligibility benchmark_derived_model Identity provider alias (0.94) Source label A.X-K2 Source row	n/a

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Intelligence Index

AA · index

Text · Chat / text

2376%

exact aliasverified runtime

Row details

Raw value: 23
Percentile: 76%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

23n/a

exact aliasverified runtimeContext only

Row details

Raw value: 23
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

GPQA

AA · %

Text · Reasoning / math / science

76.8%67.7%

exact aliasverified runtime

Row details

Raw value: 76.8%
Percentile: 67.7%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

85.7%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 85.7%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

Humanity's Last Exam

AA · %

Text · Reasoning / math / science

13.7%65.2%

exact aliasverified runtime

Row details

Raw value: 13.7%
Percentile: 65.2%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

29.6%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 29.6%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

CritPt

AA · %

Text · Reasoning / math / science

1.4%69.7%

exact aliasverified runtime

Row details

Raw value: 1.4%
Percentile: 69.7%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

8.9%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 8.9%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

SciCode

AA · %

Code · Coding

54.5%76.8%

exact aliasverified runtime

Row details

Raw value: 54.5%
Percentile: 76.8%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Medium)

Source row

41%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 41%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

AA-Omniscience accuracy

AA · %

Text · Chat / text

45.6%86.5%

exact aliasverified runtime

Row details

Raw value: 45.6%
Percentile: 86.5%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

18.6%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 18.6%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

AA-Omniscience non-hallucination

AA · %

Text · Chat / text

7.3%16.4%

exact aliasverified runtime

Row details

Raw value: 7.3%
Percentile: 16.4%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

67%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 67%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

Long Context Reasoning

AA · %

Document · Long context

64%61.5%

exact aliasverified runtime

Row details

Raw value: 64%
Percentile: 61.5%
Last updated: recent
Eligibility: headline eligible
Identity: provider alias (0.94)
Source label: GPT-5.5 (Non-reasoning)

Source row

70%n/a

exact aliasverified runtimeContext only

Row details

Raw value: 70%
Percentile: n/a
Last updated: recent
Eligibility: benchmark_derived_model
Identity: provider alias (0.94)
Source label: A.X-K2

Source row

n/a

GPT-5.5 vs A.X-K2

GPT-5.5

GPT-5.5 leads this compare set for everyday chatbot.

A.X-K2

GPT-5.5 case

A.X-K2 case

What changes the outcome

Why this result is surprising

Why this is not a clean win

Share the recommendation with the source data attached.

Open or copy the stable surfaces

Use the exact public framing

Pick the voice before you post

Compose a post that keeps the warning attached

Decisive benchmarks

Loading model comparison.

GPT-5.5 vs A.X-K2

GPT-5.5

GPT-5.5 leads this compare set for everyday chatbot.

A.X-K2

GPT-5.5 case

A.X-K2 case

What changes the outcome

Why this result is surprising

Why this is not a clean win

Share the recommendation with the source data attached.

Open or copy the stable surfaces

Use the exact public framing

Pick the voice before you post

Compose a post that keeps the warning attached

Decisive benchmarks