Quick verdict

ChatGPT or Claude Sonnet 5.5?

Choose ChatGPT when general productivity, coding, research, files, images and long-running agent work is the closer match. Choose Claude Sonnet 5.5 when full-stack software development, automated ui testing and production agent workflows matters more. Test both on the same real tasks before moving a production workflow.

Choose ChatGPT for

General productivity, coding, research, files, images and long-running agent work

Choose Claude Sonnet 5.5 for

Full-stack software development, automated UI testing and production agent workflows

OpenAI · Product

ChatGPT

General productivity, coding, research, files, images and long-running agent work

Official specification ↗
Anthropic · Model

Claude Sonnet 5.5

Anthropic's workhorse model with enhanced computer use and sub-second token generation.

Official specification ↗
01

Side-by-side comparison

CategoryChatGPTClaude Sonnet 5.5
ProviderOpenAIAnthropic
TypeProduct · General AssistantModel · Balanced reasoning model
Pricing summaryFree; Go $8/mo; Plus $20/mo; Pro $200/mo; Pro 500 $500/mo (US reference)$2 input, $0.20 cache read and $10 output per 1M tokens
Input priceProduct or plan pricing$2 / 1M tokens
Cached inputNot directly comparable$0.20 / 1M tokens
Output priceProduct or plan pricing$10 / 1M tokens
Context windowVaries by included model and plan500K tokens
Maximum outputVaries by included model and surface128K tokens
Knowledge cutoffModel-dependent; web access may add current informationAugust 2026
ReasoningVaries by selected model or modeAdaptive thinking with custom effort
Relative speedVaries by model, plan and workloadHigh throughput
Input modalitiesSee documented product featuresText and image
Output modalitiesSee documented product featuresText
Tools and integrationsGPT-6 Sol on paid plans; GPT-6 Luna on Free/Go; Intelligent UI widgets; Multi-agent collaborative Canvas editing for documents and code; Dots: always-on background agents powered by GPT-6 Astra; Deep research, data analysis, voice and custom Dots agent notificationsClaude API tool use, desktop computer use, Claude Code
API / accessProduct surface; see official source for API availabilityClaude Messages API
Best fitGeneral productivity, coding, research, files, images and long-running agent workFull-stack software development, automated UI testing and production agent workflows
CompanyOpenAIAnthropic
Product categoryProduct · General AssistantModel · Balanced reasoning model
Current pricing noteFree; Go $8/mo; Plus $20/mo; Pro $200/mo; Pro 500 $500/mo (US reference)$2 input, $0.20 cache read and $10 output per 1M tokens
Best suited toGeneral productivity, coding, research, files, images and long-running agent workFull-stack software development, automated UI testing and production agent workflows
Key capabilitiesGPT-6 Sol on paid plans; GPT-6 Luna on Free/Go; Intelligent UI widgets; Multi-agent collaborative Canvas editing for documents and code; Dots: always-on background agents powered by GPT-6 Astra; Deep research, data analysis, voice and custom Dots agent notificationsSub-second latency; Enhanced desktop computer use; 500K context; Claude Code default
Last verified2026-11-022026-10-15
Official product sourcehttps://openai.com/index/intelligent-ui-and-gpt-6-family/https://platform.claude.com/docs/en/models/sonnet-5-5/overview
02

How we reached this verdict

We looked at the things that affect everyday use: what each product can do, how its plans are structured, where it fits into your existing workflow, and what the provider currently documents. Benchmark results are useful context, but they are not a universal winner score because test settings and tools vary.

03

Common questions

ChatGPT or Claude Sonnet 5.5: which should I choose?

Choose ChatGPT for general productivity, coding, research, files, images and long-running agent work. Choose Claude Sonnet 5.5 for full-stack software development, automated ui testing and production agent workflows. Validate the decision with your own prompts and total task cost.

Is ChatGPT cheaper than Claude Sonnet 5.5?

Pricing units can differ. ChatGPT: Free; Go $8/mo; Plus $20/mo; Pro $200/mo; Pro 500 $500/mo (US reference). Claude Sonnet 5.5: $2 input, $0.20 cache read and $10 output per 1M tokens. Check tool charges, plan limits, caching and long-context rules before comparing totals.

Which is better for coding and agent work?

Capability depends on the selected product surface, tools and harness. ChatGPT is positioned for general productivity, coding, research, files, images and long-running agent work; Claude Sonnet 5.5 is positioned for full-stack software development, automated ui testing and production agent workflows. Run the same repository task on both.

How do their context windows compare?

ChatGPT lists Varies by included model and plan; Claude Sonnet 5.5 lists 500K tokens. A larger limit does not by itself guarantee better retrieval or lower cost.

04

Official sources

Use these provider pages to confirm current features, pricing and availability.

AI tools change quickly. We checked this page on 2026-09-08. Before you subscribe, confirm the latest price, regional availability and usage limits on the provider website.