AI model comparison

GPT-4.1 vs Gemini 2.5 Pro

Comparing two large-context flagships for long-document processing, retrieval-augmented generation, and code-heavy development work.

Pricing & context

All figures below are list prices pulled directly from the Harpd pricing registry (last verified 2026-08-18). Prices change often — open each model’s source link to confirm before budgeting.

MetricGPT-4.1Gemini 2.5 Pro
ProviderOpenAIGoogle
Input / 1M tokens$2$1
Output / 1M tokens$8$10
Cached input / 1M tokens$0.2$0.13
Batch discount50% off50% off
Context window1,000,000 tokens1,000,000 tokens
SourceOpenAI pricing ↗Google pricing ↗
GPT-4.1

Capabilities

GPT-4.1 pairs a 1M token context window with strong code generation and instruction-following, plus prompt caching to reduce repeat-prefix cost.

Gemini 2.5 Pro

Capabilities

Gemini 2.5 Pro also provides a 1M token context window, adds native multimodal input and strong reasoning, and includes prompt caching for long-context use.

Recommendation

Both models sit at the top of the capability range and share a 1M-token context, so either can handle very long inputs. The better fit depends on whether your workload is code-centric, multimodal, or reasoning-heavy, and on which passes your acceptance bar. Price alone will not tell you which is safe to adopt — measure both on your real tasks.

Updated 2026-08-18.

Answer

Price tells you what a model costs. It does not tell you whether it can replace your current model on your real tasks.

Evidence
  • Benchmarks measured on Harpd are planned — see /benchmarks/.

Frequently asked questions

How do I know if a cheaper model is safe to use?
Price only tells you cost, not whether a model preserves your quality bar on real work. The safe path is to run a representative sample of your actual tasks through both models and compare outputs against your acceptance criteria. Harpd’s ModelSwitch does exactly this — it switches only once a cheaper model passes your tasks, not on price alone.
Is price a good proxy for quality?
No. List price reflects positioning and context length, not how a model performs on your specific workload. A cheaper model can be better for narrow tasks and worse for others. Treat price as one input to a cost-vs-capability decision, and validate capability with real-task testing rather than assuming a ranking.
What is cost per successful task?
Cost per successful task divides your total spend by the tasks that actually succeeded, folding in retries and failures that still cost tokens. A model with a lower per-token price can end up more expensive per successful task if it fails or retries more often. See /cost-per-successful-task/ for the full method.
How does ModelSwitch test a replacement model?
ModelSwitch runs your real tasks against a candidate model and compares results to your current one using your defined acceptance checks. It switches only when the cheaper model passes, and reports the measured savings. It does not rely on published benchmarks or price as a proxy for quality.