Claude Sonnet 5.5 vs GPT-4.1: price, context and capabilities

Choose Claude Sonnet 5.5 for reused prompts and documents (RAG, agents), reasoning over long documents, the latest release and the most recent knowledge. Choose GPT-4.1 for high-volume, cost-sensitive work and writing and code generation.

In short

  • GPT-4.1 is 13% cheaper than Claude Sonnet 5.5 at the headline price ($3.50 / 1M tokens vs $4.00 / 1M tokens).
  • GPT-4.1 reads more per request: 1.05M tokens against 1M.
  • Claude Sonnet 5.5 is the newer model (September 2026, against Apr 14, 2025).
  • Only Claude Sonnet 5.5 offers reasoning.

Open in the full comparison table

What a month costsAt 20 million input and 5 million output tokens a month.
  1. Claude Sonnet 5.5Anthropic$90.00
  2. GPT-4.1OpenAI$80.00

Try your own volumes in the calculator

Which should you choose?

Each answer below comes straight from the published prices, specifications and independent benchmark results.

High-volume, cost-sensitive work

Choose GPT-4.1

GPT-4.1 costs 13% less on a typical mix of three input tokens for every output token ($3.50 against $4.00 per million tokens).

Writing and code generation

Choose GPT-4.1

GPT-4.1 charges $8.00 per million output tokens, against $10.00 for Claude Sonnet 5.5. Output dominates the bill when answers are long.

Reused prompts and documents (RAG, agents)

Choose Claude Sonnet 5.5

Claude Sonnet 5.5 charges $0.10 per million cached input tokens, against $0.50 for GPT-4.1.

Reasoning over long documents

Choose Claude Sonnet 5.5

Claude Sonnet 5.5 scores 82.7% on Long-context reasoning (AA-LCR), against 68.3% for GPT-4.1.

Latest release

Choose Claude Sonnet 5.5

Claude Sonnet 5.5 is the newer release (September 2026, against Apr 14, 2025 for GPT-4.1).

Most recent knowledge

Choose Claude Sonnet 5.5

Claude Sonnet 5.5 was trained on data up to June 2026, against June 2024 for GPT-4.1.

Monthly cost at three volumes

VolumeClaude Sonnet 5.5GPT-4.1Difference
Prototype: 1M input, 250K output tokens $4.50 $4.00 GPT-4.1, $0.50 less
Production: 20M input, 5M output tokens $90.00 $80.00 GPT-4.1, $10.00 less
Scale: 500M input, 100M output tokens $2,000 $1,800 GPT-4.1, $200.00 less

Standard rates, without caching or batch discounts. Volumes are per month.

Specifications side by side

Claude Sonnet 5.5GPT-4.1
ProviderAnthropicOpenAI
CategoryLanguage modelsLanguage models
StatusGenerally availableDeprecated
Headline price$4.00 / 1M tokens$3.50 / 1M tokens
Input$2.00 / 1M tokens$2.00 / 1M tokens
Output$10.00 / 1M tokens$8.00 / 1M tokens
Cached input$0.10 / 1M tokens$0.50 / 1M tokens
Context window1M1.05M
Max output128k33k
ReleasedSeptember 2026Apr 14, 2025
Knowledge cutoffJune 2026June 2024
LicenceProprietaryProprietary
CapabilitiesVision, Reasoning, Tool calling, Structured output, Prompt caching, Batch APIVision, Tool calling, Structured output, Prompt caching, Batch API
API model idclaude-sonnet-5-5gpt-4.1

Benchmarks side by side

Leader in bold.

BenchmarkClaude Sonnet 5.5GPT-4.1
Humanity's Last Exam 55% 4.2%
Long-context reasoning (AA-LCR) 82.7% 68.3%
Intelligence Index 56 No data
SciCode 61% No data
Terminal-Bench Hard No data 13.6%
GPQA Diamond No data 66.6%
IFBench (instruction following) No data 43%
τ²-Bench (agentic tool use) No data 47.1%
MMMU-Pro (visual reasoning) No data 61.2%

Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.

Frequently asked questions

Should I choose Claude Sonnet 5.5 or GPT-4.1?

Choose Claude Sonnet 5.5 for reused prompts and documents (RAG, agents), reasoning over long documents, the latest release and the most recent knowledge. Choose GPT-4.1 for high-volume, cost-sensitive work and writing and code generation.

Which is cheaper, Claude Sonnet 5.5 or GPT-4.1?

GPT-4.1 is 13% cheaper than Claude Sonnet 5.5 at the headline price ($3.50 / 1M tokens vs $4.00 / 1M tokens).

Which has the larger context window, Claude Sonnet 5.5 or GPT-4.1?

GPT-4.1 reads more per request: 1.05M tokens against 1M.

What is the difference between Claude Sonnet 5.5 and GPT-4.1?

Claude Sonnet 5.5 is made by Anthropic and GPT-4.1 by OpenAI. GPT-4.1 is 13% cheaper than Claude Sonnet 5.5 at the headline price ($3.50 / 1M tokens vs $4.00 / 1M tokens). GPT-4.1 reads more per request: 1.05M tokens against 1M. Claude Sonnet 5.5 is the newer model (September 2026, against Apr 14, 2025). Only Claude Sonnet 5.5 offers reasoning.

How much do Claude Sonnet 5.5 and GPT-4.1 cost per month?

At 20 million input and 5 million output tokens a month, Claude Sonnet 5.5 costs $90.00 and GPT-4.1 costs $80.00, at standard rates.

Which is newer, Claude Sonnet 5.5 or GPT-4.1?

Claude Sonnet 5.5 was released on September 2026 and GPT-4.1 on Apr 14, 2025.