Claude Sonnet 5

Text & chatNewAvailable
by AnthropicModel ID: claude-sonnet-5

Anthropic's Sonnet model with the best combination of speed and intelligence. 1M-token context window, up to 128K output tokens, adaptive thinking.

Price · 1M in / out
US$2.40 / US$12.00
Context
1 000 000 tokens
Max. output
128 000 tokens
Input → output
Text + Image → Text
Developer
Anthropic
Updated
23 September 2026
01

Playground

Try Claude Sonnet 5

Chat

US$2.40/1M in
Try Claude Sonnet 5

Send a message. The answer arrives in full once the model is done (no streaming).

System prompt
Max. answer length (tokens)

This run

at most US$0.0123 · 1.23 credits reserved

Billed by the tokens actually used; the unused part of the reservation is refunded.

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5 free credits (US$0.05) when you sign up with Google

Usable 24 hours after sign-up, up to 5 runs per day and at most 2 credits per run. Other sign-in methods start without credits. Enough for 4 runs of this model.

02

About Claude Sonnet 5

TL;DRAs of 23 September 2026

Claude Sonnet 5 is a model by Anthropic in the Text & chat category. On Railwail, Claude Sonnet 5 costs US$2.40 per 1M input tokens and US$12.00 per 1M output tokens. The context window holds 1 000 000 tokens, and one response can be up to 128 000 tokens long.

Claude Sonnet 5 is the current model in Anthropic's Sonnet tier, described by Anthropic as the best combination of speed and intelligence. It accepts text and image input, has a 1M-token context window and returns up to 128K output tokens. It uses adaptive thinking with high as the default effort; sampling parameters such as temperature are not accepted. Reliable knowledge cutoff: January 2026.
03

Pricing

Prices in US dollars. Usage is charged from prepaid credits.
InputUS$2.40 / 1M tokens
OutputUS$12.00 / 1M tokens
  • Billed by the tokens each request actually uses.
  • 1 credit = US$0.01

Cost calculator

Price calculator

/ req.
/ req.

Total

US$0.84

84 credits

Per request

US$0.0084 · 0.84 credits

Each request is rounded up to 0.01 credits.

04

API

Call Claude Sonnet 5 with your Railwail API key. Use this model ID in the request:
curl https://railwail.com/api/v1/chat/completions \
  -H "Authorization: Bearer $RAILWAIL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-5",
    "messages": [
      {
        "role": "user",
        "content": "Explain what a vector database is in two sentences."
      }
    ],
    "max_tokens": 1024
  }'
Set your key as RAILWAIL_API_KEYCreate API key
05

Specifications

Model ID
claude-sonnet-5
Developer
Anthropic
Category
Text & chat
Input
Text, Image
Output
Text
Context window
1 000 000 tokens
Max. output
128 000 tokens
Billing
By usage (tokens or GPU time)
Released
30 June 2026
Lifecycle
Current version
Catalog entry updated
23 September 2026

Input parameters

Inputs and settings from the model's input schema. The example in the API section shows which of them the API accepts.

  • promptrequired

    User message

    Type: Text
    Default:
    Allowed values: up to 32 000 characters
  • stream
    Type: Yes/no
    Default: false
    Allowed values:
  • max_tokens
    Type: Integer
    Default: 4096
    Allowed values: 1 to 128 000
  • system_prompt

    Optional system instruction

    Type: Text
    Default:
    Allowed values: up to 8000 characters

Tags

  • anthropic
  • claude
  • sonnet
  • balanced
  • agentic
  • coding
  • vision
  • long-context
  • 1m-context
06

Use cases

07

Frequently asked questions

What is Claude Sonnet 5?

Claude Sonnet 5 is a model by Anthropic in the Text & chat category. On Railwail you can call it with an API key through the Railwail API.

How much does Claude Sonnet 5 cost on Railwail?

On Railwail, Claude Sonnet 5 costs US$2.40 per 1M input tokens and US$12.00 per 1M output tokens. You are charged for what each request actually uses. Usage is paid from prepaid credits; 1 credit equals US$0.01.

What is the context window of Claude Sonnet 5?

The context window of Claude Sonnet 5 holds 1 000 000 tokens. One response can be up to 128 000 tokens long.

How fast is Claude Sonnet 5?

There are not enough measured runs of Claude Sonnet 5 on Railwail yet to state a run time. It depends on the input, the settings and the load at the provider.

Is Claude Sonnet 5 better than Claude Fable 5.1?

That depends on the task. Claude Sonnet 5 (Anthropic) and Claude Fable 5.1 (Anthropic) are both models in the Text & chat category. The comparison page shows their prices and specifications side by side.

Compare Claude Sonnet 5 and Claude Fable 5.1

Can Claude Sonnet 5 process images?

Yes. Claude Sonnet 5 accepts images as input in addition to text.

How do I use Claude Sonnet 5 through the API?

Create a Railwail API key and send your request with the model ID claude-sonnet-5. Code examples for curl, Python and JavaScript are in the API section of this page.

08

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Use Claude Sonnet 5 via the API

One API key for every model on Railwail. Usage is charged from prepaid credits, 1 credit = US$0.01.