Undominated.ai

Model comparison · accepted catalogue facts 2026-10-21

Gemini 3.6 Flash vs GPT-5.5

A quality score or a computable price is missing. This pair has no better-and-cheaper verdict.

Editorial comparison: Flagship capability vs high-speed tier: Gemini 3.6 Flash (Google) vs GPT-5.5 (OpenAI) Inclusion does not recommend either model.

Gemini 3.6 Flash

LMArena general · Elo · higher is better

Scale starts at 1040 Elo

1479.5

Balanced effective USD / 1M tokens · lower is better

Unknown

GPT-5.5

LMArena general · Elo · higher is better

Scale starts at 1040 Elo

1466.9

Balanced effective USD / 1M tokens · lower is better

$11.25/M

In-Depth Analysis

Gemini 3.6 Flash vs GPT-5.5: Measured Technical Breakdown

Comprehensive comparison across measured human-preference evaluation, effective production token costs, architectural limits, and migration trade-offs.

Measured Capability (LMArena)
Gemini 3.6 Flash leads by 12.6 Elo

Gemini 3.6 Flash: 1479.5 ±4.4 · GPT-5.5: 1466.9 ±3.65 Statistically significant preference separation

Cost Comparison Across Canonical Production Workloads

Rates represent effective cost per 1M tokens under standard token blends. Cached prompt reads are factored according to workload context reuse.

Workload & RatioGemini 3.6 FlashGPT-5.5Cost DifferenceAdvantage
Balanced 3 tokens in per 1 outSeparately billed reasoning tokens are not part of this token blend.$11.25 /1M tokens—Custom quote needed
Summarise Huge input, tiny outputSeparately billed reasoning tokens are not part of this token blend.$4.97 /1M tokens—Custom quote needed
Chat Long cached system promptSeparately billed reasoning tokens are not part of this token blend.$13.65 /1M tokens—Custom quote needed
Code gen Output dominatesSeparately billed reasoning tokens are not part of this token blend.$19.64 /1M tokens—Custom quote needed
Agentic Context replayed each turnSeparately billed reasoning tokens are not part of this token blend.$6.07 /1M tokens—Custom quote needed

Architectural & Operational Specifications

SpecificationGemini 3.6 FlashGPT-5.5Operational Note
Context window1,048,576 tokens1,050,000 tokens—
Max output generation65,536 tokens128,000 tokensGPT-5.5 allows longer single-turn completions
Base input price$0.750 / 1M tokens$5.00 / 1M tokensGemini 3.6 Flash input rate is cheaper
Base output price$3.75 / 1M tokens$30.00 / 1M tokensGemini 3.6 Flash output rate is cheaper
Cached input price$0.075 / 1M tokens$0.500 / 1M tokensGemini 3.6 Flash offers lower cached prompt cost
Reasoning & thinking tokensSupported; separately billed at $3.75/1MSupported; standard rates—
Input modalitiestext, image, video, file, audiofile, image, text—
Tool calling / function useSupportedSupported—
Open weights & licenceProprietary (proprietary)Proprietary (proprietary)—
Provider & reseller marketGoogle · 7 provider offersOpenAI · 7 provider offers (2.2× spread)—

When to Choose Gemini 3.6 Flash

  • Higher measured general capability (1479.5 Elo on human evaluation).
  • Broader multimodal input support: text, image, video, file, audio.
  • Direct integration with Google tooling and API features.
Risks when moving from GPT-5.5 → Gemini 3.6 Flash:
  • Context window: 1,050,000 → 1,048,576 tokens.
  • Output limit: 128,000 → 65,536 tokens.

When to Choose GPT-5.5

  • Larger context window (1,050,000 tokens) for long-document or repo-level context.
  • Higher maximum completion limit (128,000 tokens).
  • Direct integration with OpenAI tooling and API features.
Risks when moving from Gemini 3.6 Flash → GPT-5.5:
  • video input is not supported by the candidate.
  • audio input is not supported by the candidate.

Detailed Evidence Passports & Independent Audits

Gemini 3.6 Flash Full model card, pricing ladder & provider offers → GPT-5.5 Full model card, pricing ladder & provider offers → Alternatives to Gemini 3.6 Flash Better-and-cheaper dominance audit → Alternatives to GPT-5.5 Better-and-cheaper dominance audit →

Compare · model decision

Choose two or three models

Inspect the differences, estimate your workload and keep the evidence. All standard catalogue models are available, including unrated ones.

Catalogue facts
2026-10-21

2 / 3 selected · 0 requirements
Open public comparison link
Public workload and requirements

These settings are included in the share link. The fixed-request scenario and private evaluation data below are excluded.

A ↔ B

A quality score or a computable price is missing. This pair has no better-and-cheaper verdict.

Estimated blend: 75% input, 25% output; 0% cached input. Base context tier. Prompt length selects the billing tier. An unlisted cache-read rate uses that tier’s full input rate in this blend; missing required input or output rates prevent an estimate. The fixed-request estimate below validates actual context and output limits and requires a published cache-read rate when cache hits are assumed.

What changes between these models

Quality first, then estimated price. LMArena scores are human-preference measurements, not a benchmark of your application. A missing score is unrated.

  • Gemini 3.6 Flash · Meets the stated model requirements
  • GPT-5.5 · Meets the stated model requirements
Material differences and unknown evidence. Deltas compare each model with model A. Unknown facts remain visible.
Measured factA Gemini 3.6 FlashB GPT-5.5
LMArena general score (Elo)1,479.51,466.9Δ vs A: -12.6 Elo
Score interval half-width (± Elo)4.43.65Δ vs A: -0.75 Elo
Benchmark reasoning efforthighdefault
LMArena document score (Elo)1,456.11,485.7Δ vs A: +29.6 Elo
Estimated effective USD / 1M tokensUnknown$11.25
Base input USD / 1M tokens$0.75$5Δ vs A: +4.25 USD/M
Base output USD / 1M tokens$3.75$30Δ vs A: +26.25 USD/M
Base cached-input USD / 1M tokens$0.075$0.5Δ vs A: +0.425 USD/M
Context window (tokens)1,048,5761,050,000Δ vs A: +1,424 tokens
Output limit (tokens)65,536128,000Δ vs A: +62,464 tokens
Input modalitiestext, image, video, file, audiofile, image, text
Model providerGoogleOpenAI
Distinct sellers in the catalogue13Δ vs A: +2
Recorded retirement dateUnknownUnknown
6 shared measured facts
Shared measured facts. Deltas compare each model with model A. Unknown facts remain visible.
Measured factA Gemini 3.6 FlashB GPT-5.5
Tool useSupportedSupportedΔ vs A: 0
ReasoningSupportedSupportedΔ vs A: 0
Open weightsNot supportedNot supportedΔ vs A: 0
Recorded licenceproprietaryproprietary
Serving precision differs across offersNot supportedNot supportedΔ vs A: 0
Retirement evidenceNone announced; not a guaranteeNone announced; not a guarantee

Provider counts and precision flags describe catalogue offers. They do not establish the precision, availability, region, tool behaviour or limits of your chosen endpoint. Open each model’s provider table before switching.

Complete price ladders and billing conditions

Gemini 3.6 Flash

Estimate unavailable: Separately billed reasoning tokens are not part of this token blend.

Separate reasoning: $3.75/1M tokens; reasoning-token counts are not modelled here. Rates below are USD per 1M tokens. A threshold selects that whole input/output rate pair.

Input-token thresholdInputOutputCached input
Base, up to and including first threshold$0.75$3.75$0.075

GPT-5.5

Rates below are USD per 1M tokens. A threshold selects that whole input/output rate pair.

Input-token thresholdInputOutputCached input
Base, up to and including first threshold$5$30$0.5
> 272,000$10$45$1
Migration preflight · compare each candidate with model A

Keeping Gemini 3.6 Flash is a valid decision. No pairwise comparison certifies a drop-in replacement.

Gemini 3.6 Flash → GPT-5.5

Known loss or failed requirement

  • video input is not supported by the candidate.
  • audio input is not supported by the candidate.
  • Provider endpoint, serving precision, availability and task success need your own verification. Catalogue model capabilities do not certify an endpoint.
Check alternatives to Gemini 3.6 Flash

Estimate a fixed request shape

Private to this tab unless you save locally or explicitly export private details. These are estimates, not observed invoices. Cross-model token counts and task success are assumptions.

0.1 extra attempts means 10 extra full attempts per 100 requests. Cache writes, tool charges, taxes and unlisted charges are excluded.

  • Gemini 3.6 FlashEstimated total: unknown Separately billed reasoning tokens are not part of this request shape.
  • GPT-5.5Estimated total: $25 1,000 full attempts · base rates
Prompt and output sensitivity · sampled scenarios

Every point recalculates the entire request shape. Tier-boundary samples include one token below, at and above each threshold. Ordering between samples is not guaranteed. Lowest known cost excludes unknown estimates and is not a replacement recommendation.

Vary input; hold output, requests, cache and retries fixed.
Input tokensGemini 3.6 FlashGPT-5.5Coverage
2,000unknownSeparately billed reasoning tokens are not part of this request shape.$25Lowest knownIncomplete
4,096unknownSeparately billed reasoning tokens are not part of this request shape.$35.48Lowest knownIncomplete
32,768unknownSeparately billed reasoning tokens are not part of this request shape.$178.84Lowest knownIncomplete
131,072unknownSeparately billed reasoning tokens are not part of this request shape.$670.36Lowest knownIncomplete
271,999unknownSeparately billed reasoning tokens are not part of this request shape.$1,374.995Lowest knownIncomplete
272,000unknownSeparately billed reasoning tokens are not part of this request shape.$1,375Lowest knownIncomplete
272,001unknownSeparately billed reasoning tokens are not part of this request shape.$2,742.51Lowest knownIncomplete
Vary output; hold input, requests, cache and retries fixed.
Output tokensGemini 3.6 FlashGPT-5.5
128unknownSeparately billed reasoning tokens are not part of this request shape.$13.84
2,048unknownSeparately billed reasoning tokens are not part of this request shape.$71.44
8,192unknownSeparately billed reasoning tokens are not part of this request shape.$255.76

Bring your observed evaluation results

JSON is parsed locally. Prompts, filenames, individual responses and extra fields are not retained. Import only aggregate measurements for selected models. Task/version labels do not establish that two evaluations used the same dataset.

Expected format
[{"model":"provider/exact-model-id","task":"support-answer","version":"rubric-1","attempts":100,"successes":84,"costUsd":2.4,"latencyMs":950}]

Use the exact catalogue ID. Replace the example values with observed measurements. Omit costUsd or latencyMs when they are unknown. No public score is inferred from these observations.

Keep the decision and its evidence

A portable record retains selected facts, complete tier ladders, public requirements and the publication manifest. It also embeds the full permitted public catalogue to verify the input artifact checksum. Files are larger for this reason (up to 2 MB); local storage is limited to 12 records. Team review is local to this browser; there is no hosted collaboration.

Saving is opt-in and includes private review fields. Shared comparison links never include them. Version 1 Check references remain separate and are not overwritten or guessed into this format.

Saved local decisions · 0

No version 2 decision records are stored in this browser.

Questions this page answers

Is Gemini 3.6 Flash a better-and-cheaper replacement for GPT-5.5?

A quality score or a computable price is missing. This pair has no better-and-cheaper verdict.

Which model is higher rated: Gemini 3.6 Flash or GPT-5.5?

Gemini 3.6 Flash scores higher on LMArena general (1479.5 ±4.4) compared to GPT-5.5 (1466.9 ±3.7), a margin of 12.6 Elo points. The measured confidence intervals do not overlap, demonstrating a statistically significant preference lead on human evaluations.

Which model is more cost-effective: Gemini 3.6 Flash or GPT-5.5?

Gemini 3.6 Flash bills reasoning tokens separately. Direct pricing comparison requires evaluating your specific input/output prompt ratios and reasoning settings.

How do their context windows and generation limits compare?

Gemini 3.6 Flash provides a 1,048,576-token context window with a maximum output limit of 65,536 tokens. GPT-5.5 provides a 1,050,000-token context window with a maximum output of 128,000 tokens.

What capabilities are lost when switching between Gemini 3.6 Flash and GPT-5.5?

Switching from Gemini 3.6 Flash to GPT-5.5 involves: video input is not supported by the candidate; audio input is not supported by the candidate. Conversely, moving from GPT-5.5 to Gemini 3.6 Flash involves: Context window: 1,050,000 → 1,048,576 tokens; Output limit: 128,000 → 65,536 tokens. Run test suites on your specific prompt templates and tool declarations before cutting over production traffic.

Can Gemini 3.6 Flash or GPT-5.5 be self-hosted or deployed privately?

Both Gemini 3.6 Flash and GPT-5.5 are proprietary cloud models offered via managed API endpoints. Gemini 3.6 Flash is served by Google and 7 catalogue offers, while GPT-5.5 is served by OpenAI and 7 catalogue offers.

What is included in this comparison?

Accepted model capabilities, context and output limits, complete price-tier ladders, independent LMArena measurements and missing evidence. Provider endpoint precision and application success still need verification.

Can I compare a different workload or keep a decision record?

Yes. Change the public workload, prompt length and requirements in the comparison workspace. Fixed-request scenarios, aggregate evaluations and review notes stay local unless explicitly exported.

Evidence & Ask
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