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AI conversation model
Anthropic
Claude

Claude Sonnet 4.5

Kyeo AI offers Claude Sonnet 4.5 as a text-only chat model for demanding analysis and writing, with up to 20,000 characters per message, 40 submitted messages of history, and at most 4,096 output tokens per response.

Capability
Text chat
Credit cost
Token-based pricing
Prompt limit
20,000 characters
Upload limit
No attachments
Processes text with a 4,096-token output cap per response
Does not expose images, search, tools, thinking, or effort
Base rates are 170 input and 855 output credits per million tokens, with 0.1× cache reads and 1.25×/2× cache writes.
Suited to high-impact writing, research synthesis, and complex review
30-second overview
Claude
Token-based pricing
What it does best
Claude Sonnet 4.5 on Kyeo AI is a text-only compatibility option for established Claude workflows, not Anthropic’s newest Sonnet generation.
Best for
Regression testing existing Sonnet 4.5 prompts, text analysis and revision, code explanation, structured drafts, and controlled comparisons with newer versions.
Popular searches
How do I use Claude Sonnet 4.5?What is the current price of Claude Sonnet 4.5?How does Claude Sonnet 4.5 differ from Claude Haiku 4.5?

At a glance

What is this model like?

Use representative non-sensitive samples to evaluate quality, truncation, role behavior, actual token use, cache use, latency, and privacy. This page describes Kyeo AI's current product limits, not every feature available from the model vendor.

What it does best
Claude Sonnet 4.5 on Kyeo AI is a text-only compatibility option for established Claude workflows, not Anthropic’s newest Sonnet generation.
Best for
Regression testing existing Sonnet 4.5 prompts, text analysis and revision, code explanation, structured drafts, and controlled comparisons with newer versions.
Why use it on Kyeo AI
The current page deliberately focuses on text chat and exposes a clear 20,000-character input limit, 40-message history, and 4,096-token output cap.

Key facts

Quickly assess whether this model fits your use case.

Category
AI conversation model
Vendor
Anthropic
Model family
Claude
Output limit
4,096 tokens per response
Input type
Text only
Conversation history
Up to 40 submitted messages
Prompt limit
20,000 characters
Upload limit
No attachments

Also known as

The same model may appear under different names across documentation and community discussions; this list keeps them easy to search and compare.

Claude Sonnet 4 5
claude-sonnet-4-5
Anthropic Claude

Common questions

These practical questions focus on the task, input conditions, and result requirements you should confirm before choosing.

How do I use Claude Sonnet 4.5?
What is the current price of Claude Sonnet 4.5?
How does Claude Sonnet 4.5 differ from Claude Haiku 4.5?
How should I choose between Claude Sonnet 4.5 and Claude Sonnet 4.6?
How does Claude Sonnet 4.5 differ from GPT-5.2?
Does Claude Sonnet 4.5 currently support images?
Does Claude Sonnet 4.5 currently support web search?
Is Claude Sonnet 4.5 suitable for long-document analysis?
Is Claude Sonnet 4.5 suitable as the default workhorse?
Is Claude Sonnet 4.5 suitable for complex writing?

Selection guide

Use these decision points when choosing a model.

1
Keep 4.5 for a controlled baseline

Use it when you have validated 4.5 prompts, output formats, or human-review benchmarks and need to reproduce old results or control migration variables.

2
Compare newer generations for new work

This page is set up as the public chat entry for Claude Sonnet 4.5. That keeps the first result centered on editorial rewrites and tone-sensitive writing instead of forcing the work into a longer thread too early.

3
Claude: Balance output and credits

Test one structured-analysis task, one format-constrained rewrite, and one code-explanation task. Record first-pass acceptance, revision count, input and output tokens, and final credits. If a task needs current information, provide verified material separately because this route cannot search.

Popular comparisons

Compare common alternatives on the same task to clarify differences in inputs, controls, and cost.

How does Claude Sonnet 4.5 compare with Claude Haiku 4.5?
Claude Sonnet 4.5 vs Claude Haiku 4.5
How does Claude Sonnet 4.5 compare with Claude Sonnet 4.6?
Claude Sonnet 4.5 vs Claude Sonnet 4.6
How does Claude Sonnet 4.5 compare with GPT-5.2?
Claude Sonnet 4.5 vs GPT-5.2

Model comparison

Compare the current model with alternatives at a glance.

Role on Kyeo AI
Claude Sonnet 4.5
Legacy Sonnet compatibility baseline
Claude Haiku 4.5
Lightweight Claude entry point
Claude Sonnet 4.6
Intermediate-generation migration baseline
Visible capabilities
Claude Sonnet 4.5
Text-only Claude workspace
Claude Haiku 4.5
Text only, lower cost, lighter tasks
Claude Sonnet 4.6
Text only, intermediate-generation comparison tier
Best fit
Claude Sonnet 4.5
Long analysis, complex writing, and research synthesis
Claude Haiku 4.5
Frequent light tasks and quick summaries
Claude Sonnet 4.6
Regression testing and migration comparisons for existing Sonnet 4.6 tasks

Practical usage insights

Practical guidance based on public sources, current on-site limits, and representative tasks.

Why Claude is often considered for writing and analysis

Searchers often ask how Claude differs from GPT or Gemini for long-document summaries, complex writing, and research rather than simply asking what Claude is. These queries reflect how the model is actually used.

Benchmarks and real-world work measure different things

Benchmark sites focus on intelligence, latency, and price, while content teams care more about consistent long-form output, stylistic consistency, and whether a workflow can be standardized as a template.

Capabilities

Bounded text chat

The page accepts text only, includes at most 40 submitted messages, and caps each response at 4,096 output tokens.

Settlement from actual usage

Successful responses record base input, output, cache creation, cache read, and cache-duration usage, then settle the final charge from the reported request total.

Feature scope stays explicit

Images, web search, tools, and advanced reasoning controls are not available on this page. Use the visible controls and limits as the product contract.

Use cases

Legacy prompt regression

Replay a fixed sample set from an established Sonnet 4.5 workflow and measure format adherence, factual errors, and reviewer edits.

Structured text processing

Paste meeting notes, requirements, or code and request output under clearly defined fields.

Migration comparison

Run the same tasks on Sonnet 4.5 and a newer Kyeo AI model, then use actual acceptance rate, latency, and credits to decide whether to migrate.

Prompt tips

Define evaluation dimensions first

For analysis tasks, define the evaluation criteria and output structure before submitting the request.

Layer complex material

Provide the background first, then the source material, and finally the task requirements for more consistent results.

Verify final facts

Check time-sensitive, high-risk, and otherwise verifiable claims against independent trusted sources; do not treat fluent writing as factual evidence.

Why choose it

The current input boundary is explicitly text-only.
Supports up to 20,000 characters per message.
At most 40 submitted messages are included.
Successful responses record input and output token usage.

What to know first

This page does not claim a 1M-token context or 128K-token output; each response is capped at 4,096 output tokens.
Images, search, tools, adaptive thinking, and effort controls are not available.
Start with one representative sample using the selected settings, confirm that the result meets the objective, and only then scale up.
Before commercial use, test with your actual prompt, actual material, and actual delivery standards.

Adjustable parameters

Quickly assess whether this model fits your use case.

No additional settings are available on this page.

Credit usage

Token-based pricing

170 credits per million base input tokens and 855 per million output tokens; cache reads use 0.1× the input rate, while 5-minute and 1-hour cache writes use 1.25× and 2×.

Budget tip

Before batch generation, run an A/B test with the same assets across the current model and alternatives to validate quality and avoid wasting credits.

FAQ

Related models

Compare these similar candidates before deciding.

Claude Haiku 4.5

Claude Haiku 4.5 is a text-only Text chat entry on this site. Each new message is limited to 20,000 characters and a request includes only the 40 most recently submitted messages; images, web search, reasoning/thinking, and tool configuration are not available.

AI conversation model
Token-based pricing

Claude Sonnet 4.6

Claude Sonnet 4.6 is a text-only migration baseline on Kyeo AI between Sonnet 4.5 and Sonnet 5. It is no longer Anthropic's newest Sonnet, but remains useful for rerunning established 4.6 workflows or comparing 4.5, 4.6, and newer Kyeo AI models on the same tasks. This implementation is narrower than the official platform: each new message is limited to 20,000 JavaScript characters, only the 40 most recent messages are included, and attachments, web search, thinking, and tool execution are not exposed.

AI conversation model
Token-based pricing

Claude Opus 4.7

Kyeo AI offers Claude Opus 4.7 as a text-only chat model for demanding analysis and writing, with up to 20,000 characters per message, 40 submitted messages of history, and at most 4,096 output tokens per response.

AI conversation model
Token-based pricing

Sources

Content is based on model documentation, feature references, and the settings available on Kyeo AI.

Source note

This page describes the current Kyeo AI experience: text-only chat, up to 20,000 characters per message, the 40 most recently submitted messages, and at most 4,096 output tokens per response. Pricing and feature claims below are limited to controls that are publicly available on this page.

Last updated: 2026-08-26
Anthropic: Introducing Claude Sonnet 4.5
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Anthropic: Claude Sonnet model page
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Anthropic: Introducing Claude Sonnet 4.6
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Anthropic: Introducing Claude Sonnet 5
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Anthropic: Claude Sonnet 4.5 system card
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