Neither wins outright: Anthropic: Claude Sonnet 4 is the pick when cost matters at scale, OpenAI: GPT Chat Latest when you need to fit long inputs in one request.
| Spec | Anthropic: Claude Sonnet 4 | OpenAI: GPT Chat Latest |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input price (per 1M tokens) | $3.00 | $5.00 |
| Output price (per 1M tokens) | $15.00 | $30.00 |
| Blended price (3:1 input/output) | $6.00 | $11.25 |
| Cheaper than … of all models we track | 8% | 5% |
| Context window | 200K tokens (~300 pages) | 400K tokens (~600 pages) |
| Larger context than … of all models | 37% | 62% |
| Max output per response | 64K tokens (~48,000 words) | 128K tokens (~96,000 words) |
| Input types | image, text, file | text, image, file |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-05-22 | 2026-05-05 |
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | Anthropic: Claude Sonnet 4 | OpenAI: GPT Chat Latest | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $525 | $975 | Anthropic: Claude Sonnet 4 saves $450 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $510 | $900 | Anthropic: Claude Sonnet 4 saves $390 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $540 | $960 | Anthropic: Claude Sonnet 4 saves $420 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $330 | $580 | Anthropic: Claude Sonnet 4 saves $250 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $165 | $280 | Anthropic: Claude Sonnet 4 saves $115 |
| Capability | Anthropic: Claude Sonnet 4 | OpenAI: GPT Chat Latest | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | — | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | — | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | ✓ Yes | ✓ Yes | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | ✓ Yes | ✓ Yes | answer from live web results |
| Seed (reproducible sampling) | — | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Neither wins outright: Anthropic: Claude Sonnet 4 is the pick when cost matters at scale, OpenAI: GPT Chat Latest when you need to fit long inputs in one request. In short: Anthropic: Claude Sonnet 4 when cost matters at scale, you need reasoning / thinking mode; OpenAI: GPT Chat Latest when you need to fit long inputs in one request, you need structured output (JSON schema), you need seed (reproducible sampling), you generate long outputs in one go, you want the newer model.
Anthropic: Claude Sonnet 4 is cheaper: $6.00 vs $11.25 per 1M tokens at a typical 3:1 input/output mix, 47% less. For 50,000 support conversations a month that is $525 against $975.
Anthropic: Claude Sonnet 4 costs $3.00 per 1M input tokens and $15.00 per 1M output tokens; OpenAI: GPT Chat Latest costs $5.00 input and $30.00 output. Output tokens are billed separately, so long answers shift the gap.
OpenAI: GPT Chat Latest: 400K tokens, about 600 pages, against 200K (about 300 pages) for Anthropic: Claude Sonnet 4.
Tool calling — Anthropic: Claude Sonnet 4: yes, OpenAI: GPT Chat Latest: yes. JSON-schema structured output — Anthropic: Claude Sonnet 4: not advertised, OpenAI: GPT Chat Latest: yes.
Yes, both accept image input.
No free variant is listed for either; both are pay-per-token.
Anthropic: Claude Sonnet 4 can write up to 64K tokens (about 48,000 words) per response; OpenAI: GPT Chat Latest up to 128K (about 96,000 words).
Anthropic: Claude Sonnet 4 was listed on 2025-05-22; OpenAI: GPT Chat Latest on 2026-05-05.
Claude Sonnet 4 significantly enhances the capabilities of its predecessor, Sonnet 3.7, excelling in both coding and reasoning tasks with improved precision and controllability. Achieving state-of-the-art performance on SWE-bench (72.7%),...
Full Anthropic: Claude Sonnet 4 specs →GPT Chat Latest points to OpenAI's stable API alias `chat-latest` that always resolves to the latest Instant chat model used in ChatGPT. As OpenAI rolls out new Instant model updates...
Full OpenAI: GPT Chat Latest specs →