GoogleGemini 2.5 Flash-LiteVSOpenAIGPT-5.5

Analysis by:the whichllmmodel Editorial Team|Updated: June 2026

Our Take

We recommend GPT-5.5 if you need peak intelligence for complex complex codebases, multi-file repositories, and architectural planning, or the 64.3x cheaper Gemini 2.5 Flash-Lite if your workflow is limited to multi-file code and clearly defined tasks. While GPT-5.5 holds a major reasoning advantage, Gemini 2.5 Flash-Lite is optimized for high-volume budget pipelines. Choose GPT-5.5 for architectural codebase planning, or Gemini 2.5 Flash-Lite to maximize your budget for basic scripts.

▶WHY?

Benchmark Calculations & Evidence:

Coding Evaluation: Gemini 2.5 Flash-Lite was evaluated on SWE-bench Verified (scoring 41.3%), while GPT-5.5 was evaluated on SWE-bench Pro (scoring 58.6%).

Reasoning Accuracy: Both models were evaluated on the GPQA Diamond benchmark. GPT-5.5 scored 93.6%, while Gemini 2.5 Flash-Lite scored 62.5%.

Cost Efficiency: Gemini 2.5 Flash-Lite pricing ($0.1/M input, $0.4/M output) is 64.3x cheaper than GPT-5.5 ($5/M input, $30/M output).

Was this recommendation helpful?

Model Specs

Gemini 2.5 Flash-Lite

Website

Benchmarks & Scores

Coding (swe-bench-verified)

41.3%

multi-file code and clearly defined tasks

Reasoning (gpqa-diamond)

62.5%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)64.3x cheaper

$0.17Input: $0.10 | Output: $0.40

Context Window

1.05M tokens

Model Specs

GPT-5.5

Website

Benchmarks & Scores

Coding (swe-bench-pro)

58.6%

complex codebases, multi-file repositories, and architectural planning

Reasoning (gpqa-diamond)Winner (+31.1%)

93.6%

graduate-level science QA

Cost & Context

Cost (per 1M tokens)

$11.25Input: $5.00 | Output: $30.00

Context WindowLarger

1.05M tokens

Read our data collection methodology

Frequently Asked Questions about Gemini 2.5 Flash-Lite vs GPT-5.5

Gemini 2.5 Flash-Lite is cheaper than GPT-5.5. Gemini 2.5 Flash-Lite has a blended cost of $0.17/1M tokens, which is about 64.3x cheaper than GPT-5.5 at $11.25/1M tokens.

For coding tasks, Gemini 2.5 Flash-Lite scores 41.3% on swe-bench-verified (multi-file code and clearly defined tasks), while GPT-5.5 scores 58.6% on swe-bench-pro (complex codebases, multi-file repositories, and architectural planning).

Related Matchups

Explore similar comparisons for Gemini 2.5 Flash-Lite and GPT-5.5.

Browse More Comparisons

GoogleGemini 2.5 Flash-Lite

GoogleGemini 2.5 Flash-Lite

OpenAIGPT-5.6 Luna

Compare Specs

Do you want to find a model for your constraints?

Use our interactive model finder to filter LLMs by reasoning capability, coding performance, cost, and context length.

Open Model Finder