Model comparison

Gemini 3.6 Flash vs GPT-5.6 Terra

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

Catalog record checked September 5, 2026Individual provider fields may changeEvidence confidence: High — see receipts below

Google

Gemini 3.6 Flash

Balanced

OpenAI

GPT-5.6 Terra

Balanced

AI model capability comparison
Specification	Gemini 3.6 Flash	GPT-5.6 Terra
Provider	Google	OpenAI
Tier	Balanced	Balanced
Context window	1M	Winner: 1.05M
Max output	64K	Winner: 128K
Input / 1M tokens	Winner: $0.75	$2
Output / 1M tokens	Winner: $3.75	$12
Weights	Closed	Closed
Parameters	Not disclosedUnverified	mid-tier reasoning model
Reasoning levels	low, medium, high	none, low, medium, high, xhigh, max
Modalities	text, image, video, audio, pdf	text, image
API model id	gemini-3.6-flash	gpt-5.6-terra
Released	July 21, 2026	July 9, 2026
Artificial Analysis Intelligence Index (2026-08-14)	54	Not verifiedUnverified
Artificial Analysis Intelligence Index [high] (2026-08-14)	Not verifiedUnverified	50
Terminal-Bench 2.1 (2026-07)	78	Winner: 87.4
DeepSWE 1.1 (2026-07)	48.6	Not verifiedUnverified
Humanity's Last Exam (2026-08)	51.2	Not verifiedUnverified
SWE-bench Verified (2026-09-01)	Not verifiedUnverified	95.4
LiveBench (2026-09-05)	Not verifiedUnverified	77.9

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

2026-09-05: LiveBench official leaderboard (benchmark-owned), max effortContamination-resistant general capability across reasoning, coding, math, data analysis, and language, with monthly question refreshes. Comparability: comparable with caveat — Rolling question set: observations months apart measure different question mixes. Record the measurement date and compare within ~1 month windows.
2026-09-01: vals.ai SWE-bench Verified leaderboard (independent, mini-swe-agent bash-only) (independent; official SWE-bench not published)Real GitHub issue resolution: does the model's patch pass the hidden tests. Comparability: comparable with caveat — Post-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.
2026-08-14: Artificial AnalysisComposite index blending reasoning, knowledge, and coding evals into one 0–100 score. Comparability: directly comparable — AA occasionally rebaselines the index scale between snapshots — a score captured on one date is only comparable to same-snapshot scores (check measuredAt).
2026-08: Google DeepMind model evaluation report (vendor, HLE-Verified full set)Frontier-knowledge ceiling: extremely hard multi-domain questions written to be near-impossible without deep expertise. Comparability: comparable with caveat — Subset/tool configurations (text-only vs with-tools) differ between vendors and materially change scores; must match configuration to compare.
2026-07-09: OpenAI GPT-5.6 announcement (vendor; chart transcribed by Vellum)Agentic terminal work: multi-step tasks executed in a sandboxed shell environment. Comparability: comparable with caveat — Scores across Terminal-Bench major versions (v1 vs v2) are NOT comparable; harness configuration (container, time limits) also shifts results.
2026-07: Google DeepMind model evaluation report (vendor, quoting Datacurve leaderboard; 3.7 report shows 49 — rounding conflict preserved)Agentic terminal work: multi-step tasks executed in a sandboxed shell environment. Comparability: comparable with caveat — Scores across Terminal-Bench major versions (v1 vs v2) are NOT comparable; harness configuration (container, time limits) also shifts results.

Pricing tiers: Gemini 3.6 Flash: $0.75/$3.75 per MTok (intro through 2026-12-31, then $1.50/$7.50). Multimodal input. · GPT-5.6 Terra: Launch list was $2.50/$15; cut to $2/$12 on 2026-07-30. Cached input $0.20/MTok; batch $1/$6.

BalancedRecord checked September 5, 2026

Gemini 3.6 Flash

Gemini 3.6 Flash is Google's balanced multimodal Flash tier with a 1M-token context.

Best for

Multimodal pipelines
High-volume processing
Video and audio input

Watch out

Superseded by 3.7 Flash on quality; still a solid mid-tier.

BalancedRecord checked September 3, 2026

GPT-5.6 Terra

GPT-5.6 Terra delivers roughly GPT-5.5-class quality at about half the cost, with the full 1.05M-token context.

Best for

Cost-sensitive production
Mixed reasoning workloads
High-volume agents

Watch out

Quality trails Sol on the hardest tasks; route frontier work to Sol when it matters.

When the cheaper one wins

Gemini 3.6 Flash is cheaper on output at $3.75 per million tokens against $12 for GPT-5.6 Terra — about 3.2×. 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.

Run the model picker

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.
4/5 core specs verified on both sides — Not published for at least one side: parameter count.
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 6 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.

Gemini 3.6 Flash: Google — Gemini 3.6 Flash (accessed 2026-08-29)
Gemini 3.6 Flash: Google Cloud Gemini pricing (accessed 2026-08-29)
GPT-5.6 Terra: OpenAI — GPT-5.6 (accessed 2026-08-29)
GPT-5.6 Terra: OpenAI API pricing (gpt-5.6-terra $2/$12) (accessed 2026-08-29)

Related comparisons

Diving deeper on one model? Gemini 3.6 Flash · GPT-5.6 Terra

Common questions

Gemini 3.6 Flash vs GPT-5.6 Terra

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

Is Gemini 3.6 Flash or GPT-5.6 Terra cheaper for input?

Gemini 3.6 Flash is cheaper at $0.75 per million input tokens, against $2 for GPT-5.6 Terra — roughly 2.7× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Gemini 3.6 Flash has tiered pricing: $0.75/$3.75 per MTok (intro through 2026-12-31, then $1.50/$7.50). Multimodal input. GPT-5.6 Terra has tiered pricing: Launch list was $2.50/$15; cut to $2/$12 on 2026-07-30. Cached input $0.20/MTok; batch $1/$6.

Is Gemini 3.6 Flash or GPT-5.6 Terra cheaper for output?

Gemini 3.6 Flash is cheaper at $3.75 per million output tokens, against $12 for GPT-5.6 Terra — roughly 3.2× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Gemini 3.6 Flash has tiered pricing: $0.75/$3.75 per MTok (intro through 2026-12-31, then $1.50/$7.50). Multimodal input. GPT-5.6 Terra has tiered pricing: Launch list was $2.50/$15; cut to $2/$12 on 2026-07-30. Cached input $0.20/MTok; batch $1/$6.

Which has the larger context window, Gemini 3.6 Flash or GPT-5.6 Terra?

GPT-5.6 Terra accepts 1.05M tokens against 1M for Gemini 3.6 Flash. This only matters if you routinely send very long documents or large codebases.

Do Gemini 3.6 Flash and GPT-5.6 Terra support the same reasoning levels?

Gemini 3.6 Flash exposes low, medium, high, while GPT-5.6 Terra exposes none, low, medium, high, xhigh, max.

Should I use Gemini 3.6 Flash or GPT-5.6 Terra?

Both sit in the balanced tier, so the choice usually comes down to price and context rather than capability. Gemini 3.6 Flash suits multimodal pipelines; GPT-5.6 Terra suits cost-sensitive production.

Next step

Choosing between them

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

Input price: Gemini 3.6 Flash costs $0.75 per 1M tokens versus $2 for GPT-5.6 Terra — a 2.7x difference at the headline tier.
Context: GPT-5.6 Terra takes 1.05M against 1M for Gemini 3.6 Flash — only decisive if your prompts approach the smaller window.
Measured capability: Gemini 3.6 Flash leads Artificial Analysis Intelligence Index 54 to 50 (measured 2026-08-14).

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