Gemini 2.5 Pro vs GPT-5.3-Codex

GPT-5.3-Codex leads Gemini 2.5 Pro on coding, 60.0 to 19.1 on the Vibe Coding Index, and Gemini 2.5 Pro costs 1.4x less per output token ($10.00 vs $14.00 per million). Updated October 22, 2026; 22 benchmarks have a result for both.

Replace Gemini 2.5 Pro Replace GPT-5.3-Codex

Gemini 2.5 ProGoogle

Coding: 19.1
Overall: 41.8
Output $/M: $10.00

GPT-5.3-CodexOpenAI

Coding: 60.0
Overall: No data
Output $/M: $14.00

vs boards won of 22 shared

Gemini 2.5 Pro or GPT-5.3-Codex: which to pick

Pick GPT-5.3-Codex for coding: it scores 60.0 on the Vibe Coding Index against 19.1 for Gemini 2.5 Pro.

Pick Gemini 2.5 Pro for output tokens 1.4x cheaper ($10.00 vs $14.00 per million) and a larger context window (1.05M against 400K tokens).

Model AGemini 2.5 ProGoogle19.1/1003 independent benchmarks$0.64 per solved task Model BGPT-5.3-CodexOpenAI60.0/1003 independent benchmarks$0.59 per solved task

226812

Shared results: 22
Gemini 2.5 Pro only: 68
GPT-5.3-Codex only: 12
Like-for-like categories: 6 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

Coding
Vibe Coding Index, six public coding benchmarks
GPT-5.3-Codex
GPT-5.3-Codex scores 60.0 against 19.1.
3 benchmarks behind each score
Intelligence
AA Intelligence Index
GPT-5.3-Codex
GPT-5.3-Codex leads, 32.5 against 16.1.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Gemini 2.5 Pro has a AA Agentic Index result, 1.6.
Directional only
Web design
Design Arena: websites
Gemini 2.5 Pro
Gemini 2.5 Pro leads, 1167 against 1162.
Same board, both measured
Long documents
Listed context window
Gemini 2.5 Pro
Gemini 2.5 Pro takes 1.05M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Gemini 2.5 Pro
Gemini 2.5 Pro $0.0063, GPT-5.3-Codex $0.0088 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GPT-5.3-Codex
Gemini 2.5 Pro $0.64, GPT-5.3-Codex $0.59.
Published attempt cost and pass rate

At a glance

Coding index: Gemini 2.5 Pro 19.1 from 3 benchmarks, GPT-5.3-Codex 60.0 from 3 benchmarks.
Widest category: Coding, 33.2 points apart on average over 8 shared benchmarks.
Widest single gap: Vibe Code Bench (Vals AI): Gemini 2.5 Pro 0.4% against GPT-5.3-Codex 61.8%, 61.4 points apart on a 0 to 100 scale.
Output price: Gemini 2.5 Pro $10.00 against GPT-5.3-Codex $14.00 per million output tokens, 1.4x apart.
Context window: Gemini 2.5 Pro takes 1.05M tokens, GPT-5.3-Codex 400K.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
Category	Gemini 2.5 Pro	GPT-5.3-Codex
Coding	0	8
Intelligence	0	2
Agentic work	0	2
Reasoning	0	2
Web design	5	1
General	0	2
All shared boards	5	17

CodingLike-for-likeSix of these boards feed the Vibe Coding Index08

Coding benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
SWE-bench Verified	53.6%	Not measured	Only Gemini 2.5 Pro measured
LMArena WebDev	1226	1407	GPT-5.3-Codex
AA Coding Index	33.3	Not measured	Only Gemini 2.5 Pro measured
LiveCodeBench (Vals AI)	Not measured	87.3%	Only GPT-5.3-Codex measured
SWE-bench Verified (Vals AI)	54.4%	78.0%	GPT-5.3-Codex
Vibe Code Bench (Vals AI)	0.4%	61.8%	GPT-5.3-Codex
IOI (Vals AI)	Not measured	53.8%	Only GPT-5.3-Codex measured
LiveCodeBench (Artificial Analysis run)	80.1%	Not measured	Only Gemini 2.5 Pro measured
SciCode	46.3%	Not measured	Only Gemini 2.5 Pro measured
Terminal-Bench Hard (Artificial Analysis run)	26.5%	53.0%	GPT-5.3-Codex
Terminal-Bench	32.6%	78.4%	GPT-5.3-Codex
GSO-Bench	3.9%	Not measured	Only Gemini 2.5 Pro measured
WeirdML	54.0%	79.3%	GPT-5.3-Codex
ALE-Bench	Not measured	1655.2	Only GPT-5.3-Codex measured
LMArena Text: coding	1452	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: software and IT	1459	Not measured	Only Gemini 2.5 Pro measured
LMArena WebDev: React	Not measured	1395	Only GPT-5.3-Codex measured
LMArena WebDev: HTML	1235	1422	GPT-5.3-Codex
LMArena WebDev: from an image	1285	1443	GPT-5.3-Codex
Neither model has a result on the other 20 boards here

IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02

Intelligence benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
AA Intelligence Index	16.1	32.5	GPT-5.3-Codex
Epoch Capabilities Index	145.1	157.1	GPT-5.3-Codex

Agentic workLike-for-likePublic boards, shown as published, kept out of the index02

Agentic work benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
AA Agentic Index	1.6	Not measured	Only Gemini 2.5 Pro measured
Design Arena: agents building web apps	Not measured	1032	Only GPT-5.3-Codex measured
Design Arena: agents building full-stack apps	Not measured	983	Only GPT-5.3-Codex measured
Design Arena: agents building mobile apps	Not measured	1053	Only GPT-5.3-Codex measured
Design Arena: agents building Android apps	Not measured	1084	Only GPT-5.3-Codex measured
Design Arena: agents building Godot games	Not measured	1124	Only GPT-5.3-Codex measured
τ²-Bench Telecom	54.1%	86.0%	GPT-5.3-Codex
METR time horizons	Not measured	74.5%	Only GPT-5.3-Codex measured
GDPval	23.3%	Not measured	Only Gemini 2.5 Pro measured
DeepResearch Bench	41.5%	Not measured	Only Gemini 2.5 Pro measured
Vending-Bench 2	$574	$5,940	GPT-5.3-Codex
BrowseComp-Plus	29.5%	Not measured	Only Gemini 2.5 Pro measured
Neither model has a result on the other 29 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index02

Reasoning benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
GPQA Diamond (Artificial Analysis run)	84.4%	91.5%	GPT-5.3-Codex
Humanity's Last Exam (Artificial Analysis run)	22.5%	42.5%	GPT-5.3-Codex
GPQA Diamond (Epoch AI run)	85.3%	Not measured	Only Gemini 2.5 Pro measured
ARC-AGI	41.0%	Not measured	Only Gemini 2.5 Pro measured
ARC-AGI-2	4.9%	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: hard prompts	1455	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: expert	1452	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: hard prompts in English	1453	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: diagrams	1274	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: homework	1281	Not measured	Only Gemini 2.5 Pro measured
Kagi LLM Benchmark	70.3%	Not measured	Only Gemini 2.5 Pro measured
Neither model has a result on the other 11 boards here

MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared

Math benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
AA Math Index	87.7	Not measured	Only Gemini 2.5 Pro measured
AIME 2025 (Artificial Analysis run)	87.7%	Not measured	Only Gemini 2.5 Pro measured
OTIS Mock AIME	84.7%	Not measured	Only Gemini 2.5 Pro measured
FrontierMath, tiers 1 to 3	24.6%	Not measured	Only Gemini 2.5 Pro measured
FrontierMath, tier 4	0.0%	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: math	1450	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: mathematical work	1454	Not measured	Only Gemini 2.5 Pro measured
Neither model has a result on the other 6 boards here

KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared

Knowledge benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
CaseLaw (Vals AI)	63.9%	Not measured	Only Gemini 2.5 Pro measured
CorpFin (Vals AI)	60.8%	Not measured	Only Gemini 2.5 Pro measured
MortgageTax (Vals AI)	68.9%	Not measured	Only Gemini 2.5 Pro measured
MedCode (Vals AI)	50.6%	Not measured	Only Gemini 2.5 Pro measured
MMLU Pro (Artificial Analysis run)	86.2%	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: science	1480	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: medicine and healthcare	1476	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: legal and government	1480	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: business and finance	1439	Not measured	Only Gemini 2.5 Pro measured
FACTS Benchmark Suite	61.5%	Not measured	Only Gemini 2.5 Pro measured
Neither model has a result on the other 8 boards here

Web designLike-for-likePublic boards, shown as published, kept out of the index51

Web design benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
Design Arena: websites	1167	1162	Gemini 2.5 Pro
Design Arena: UI components	1137	1134	Gemini 2.5 Pro
Design Arena: game dev	1111	1161	GPT-5.3-Codex
Design Arena: data viz	1222	1164	Gemini 2.5 Pro
Design Arena: 3D	1080	1007	Gemini 2.5 Pro
Design Arena: all code categories	1152	1144	Gemini 2.5 Pro
Design Arena: SVG	Not measured	1129	Only GPT-5.3-Codex measured
Design Arena: ASCII art	Not measured	1152	Only GPT-5.3-Codex measured
Neither model has a result on the other 1 board here

GeneralLike-for-likePublic boards, shown as published, kept out of the index02

General benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
SAGE (Vals AI)	41.9%	Not measured	Only Gemini 2.5 Pro measured
MedScribe (Vals AI)	73.5%	Not measured	Only Gemini 2.5 Pro measured
IFBench	48.7%	75.4%	GPT-5.3-Codex
Long context reasoning (AA-LCR)	69.0%	83.3%	GPT-5.3-Codex
DTBench	82.4%	Not measured	Only Gemini 2.5 Pro measured
LMCA	34.8%	Not measured	Only Gemini 2.5 Pro measured
Creative writing (Lech Mazur)	83.8%	Not measured	Only Gemini 2.5 Pro measured
LMArena Text	1458	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: instruction following	1437	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: creative writing	1454	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision	1263	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: English	1458	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: non-English	1452	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: Chinese	1507	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: German	1487	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: Japanese	1461	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: Korean	1434	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: French	1473	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: Spanish	1474	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: Russian	1461	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: Polish	1479	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: multi-turn	1453	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: longer queries	1449	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: writing and language	1454	Not measured	Only Gemini 2.5 Pro measured
LMArena Text: entertainment and media	1441	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: English	1261	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: Chinese	1300	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: reading text	1270	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: humor	1262	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: captioning	1304	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: recognizing things	1283	Not measured	Only Gemini 2.5 Pro measured
LMArena Vision: creative writing	1265	Not measured	Only Gemini 2.5 Pro measured
LMArena Document	1421	Not measured	Only Gemini 2.5 Pro measured
Neither model has a result on the other 13 boards here

Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared

Image generation benchmarks for Gemini 2.5 Pro and GPT-5.3-Codex
Benchmark	Gemini 2.5 Pro	GPT-5.3-Codex	Leader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Gemini 2.5 Pro$0.0063Fits in one request

GPT-5.3-Codex$0.0088Fits in one request

Gemini 2.5 Pro costs less

Repository review

50K input + 3K output tokens

Gemini 2.5 Pro$0.092Fits in one request

GPT-5.3-Codex$0.130Fits in one request

Gemini 2.5 Pro costs less

Agent loop

200K input + 10K output tokens

Gemini 2.5 Pro$0.350Fits in one request

GPT-5.3-Codex$0.490Fits in one request

Gemini 2.5 Pro costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Gemini 2.5 Pro and GPT-5.3-Codex
Specification	Google Gemini 2.5 Pro	OpenAI GPT-5.3-Codex
Maker	Google	OpenAI
Weights	No public weights listed	No public weights listed
Released	June 17, 2025	February 24, 2026
Context window	1.05M	400K
Input $/Mtok	$1.25	$1.75
Output $/Mtok	$10.00	$14.00
Coding index	19.1	60.0
Independent measurements behind it	3	3
Cost per solved task	$0.64	$0.59
Source	OpenRouter listing	OpenRouter listing

Questions

Is Gemini 2.5 Pro better than GPT-5.3-Codex for coding?

Pick GPT-5.3-Codex for coding: it scores 60.0 on the Vibe Coding Index against 19.1 for Gemini 2.5 Pro. Pick Gemini 2.5 Pro for output tokens 1.4x cheaper ($10.00 vs $14.00 per million) and a larger context window (1.05M against 400K tokens).

Which is cheaper, Gemini 2.5 Pro or GPT-5.3-Codex?

Gemini 2.5 Pro costs $1.25 per million input tokens and $10.00 per million output tokens; GPT-5.3-Codex costs $1.75 and $14.00. Per solved SWE-bench Verified task, Gemini 2.5 Pro costs $0.64 and GPT-5.3-Codex $0.59.

Which has the bigger context window, Gemini 2.5 Pro or GPT-5.3-Codex?

Gemini 2.5 Pro, with 1.05M tokens against 400K.

How many benchmarks is the Gemini 2.5 Pro vs GPT-5.3-Codex comparison based on?

22 benchmarks have a result for both models as of October 22, 2026. Gemini 2.5 Pro's coding index rests on 3 independent benchmarks and GPT-5.3-Codex's on 3. Where only one model has a result, the page says so instead of naming a winner.

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Gemini 2.5 Pro or GPT-5.3-Codex: which to pick

Which one for your work

Coding

Intelligence

Agentic work

Web design

Long documents

Everyday cost

Cost per solved task

At a glance

Benchmark by benchmark

What each workload costs

Chat turn

Repository review

Agent loop

Specification differences

Questions

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