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Head-to-head comparison

Gemini 3.5 Flash Lite vs GPT-6 Astra

Gemini 3.5 Flash Lite (Google) and GPT-6 Astra (OpenAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 27 October 2026

As of 27 October 2026, GPT-6 Astra holds the stronger ModelCap Index position (#13 vs #34); and Gemini 3.5 Flash Lite is 20× cheaper per output token ($2.50/1M vs $50.00/1M).

Which should you choose?

Choose Gemini 3.5 Flash Lite if…

  • API cost matters — $2.50/1M output tokens against $50.00/1M, about 20× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.30/1M against $10.00/1M.

Choose GPT-6 Astra if…

  • you want the stronger overall ModelCap Index position — #13 against #34 (80.1 vs 72.1 points).
  • you want provider choice — 3 listed API providers against 2.
  • Arena text is your yardstick — 1476 against 1455.
  • Arena coding is your yardstick — 1543 against 1502.
  • ARC-AGI-2 is your yardstick — 95.0% against 10.3%.
  • AA Intelligence Index is your yardstick — 52.7 against 22.2.
  • you want the more recently listed model — GPT-6 Astra was listed 4 September 2026, Gemini 3.5 Flash Lite 21 July 2026.

Gemini 3.5 Flash Lite vs GPT-6 Astra: specs, pricing and context

Specification comparison of Gemini 3.5 Flash Lite and GPT-6 Astra
FieldGemini 3.5 Flash LiteGoogleGPT-6 AstraOpenAI
ModelCap Index position#34#13
Index score72.180.1
EvidenceMeasuredMeasured
Input price / 1M tokens$0.30$10.00
Output price / 1M tokens$2.50$50.00
Context window1M tokens1M tokens
Declared route output cap66K128K
API providers listed23
Weight accessNo linked weightsNo linked weights
Input modalitiesText, Image, Video, File, AudioFile, Image, Text
First listed21 July 20264 September 2026
PublisherGoogleOpenAI

Evidence: 3 public benchmark observations across 3 boards · 5 public benchmark observations across 5 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Gemini 3.5 Flash Lite vs GPT-6 Astra

Public benchmark boards where Gemini 3.5 Flash Lite or GPT-6 Astra has a published result
BoardGemini 3.5 Flash LiteGPT-6 AstraLeads
Arena textArena (LMArena)14551451–1460Not reported14761470–1483MaxGPT-6 Astra
Arena codingArena (LMArena)15021495–150815431532–1554MaxGPT-6 Astra
LMArena AgentLMArena—14.0%11.9%–16.0%MaxOnly one result
ARC-AGI-2ARC Prize Foundation10.3%High95.0%MaxGPT-6 Astra
ARC-AGI-3ARC Prize Foundation—62.7%MaxOnly one result
AA Intelligence IndexArtificial Analysis22.2Reasoning52.7MaxGPT-6 Astra
Terminal-Bench 4.0Terminal-Bench (Laude Institute)—58.2%55.4%–61.0%Codex · MaxOnly one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Gemini 3.5 Flash Lite vs GPT-6 Astra: common questions

Is Gemini 3.5 Flash Lite better than GPT-6 Astra?

GPT-6 Astra ranks higher on the ModelCap Index as of 27 October 2026: #13 against #34. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.

Is Gemini 3.5 Flash Lite cheaper than GPT-6 Astra?

Gemini 3.5 Flash Lite is cheaper on output tokens: $2.50/1M against $50.00/1M. Input tokens are $0.30/1M for Gemini 3.5 Flash Lite and $10.00/1M for GPT-6 Astra. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $1.85 for Gemini 3.5 Flash Lite versus $45.00 for GPT-6 Astra. Gemini 3.5 Flash Lite costs 95.9% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.

Which has the bigger context window, Gemini 3.5 Flash Lite or GPT-6 Astra?

Both publish a 1M-token context window. OpenRouter catalogue or provider-endpoint declaration. Limits can vary by provider and prompt length; a model-wide maximum has not been independently verified.

Which is better for coding, Gemini 3.5 Flash Lite or GPT-6 Astra?

Arena coding: Gemini 3.5 Flash Lite 1502, GPT-6 Astra 1543 — GPT-6 Astra leads.

Are Gemini 3.5 Flash Lite and GPT-6 Astra open-weight models?

Gemini 3.5 Flash Lite: No linked weights. GPT-6 Astra: No linked weights. Open weights mean the checkpoint can be downloaded and self-hosted under its licence. A missing weight link does not identify every API or chat product that offers a model.

Where can I run Gemini 3.5 Flash Lite and GPT-6 Astra?

ModelCap currently lists 2 API providers for Gemini 3.5 Flash Lite and 3 for GPT-6 Astra, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Gemini 3.5 Flash Lite vs GPT-6 Astra comparison?

Every figure and ModelCap Index position comes from the same published snapshot dated 27 October 2026. Publication and page updates happen separately; use the snapshot date shown on the page.

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