Alex Getmanearly AI signals
EN

Claude Sonnet 5.5

Anthropic

Released Updated
Context window
1M
1,000,000 tokens
Max output
128K
128,000 tokens
Input / Output
text, image → text

API pricing

USD / 1M tokens

InputOutputCached input
  • $2.00
anthropic-pricing
  • $10.00
anthropic-pricing
  • $0.10
anthropic-pricing
Calculate your workload

Timeline

  1. · Released · evidence link
Input / output price · USD / 1M tokens
ModelEvidence linksInput / output price
claude-sonnet-5-5
batch
anthropic
API route unavailable
$1.00 / $5.00
claude-sonnet-5-5
standard
anthropic$2.00 / $10.00
  1. · Evidence links · Anthropic · official articles
  2. · Evidence links · Anthropic · official articles
  3. · Evidence links · Anthropic · official articles
  4. · Alex's posts · Alex Getman
    Excerpt
    🚨 Sonnet 5.5 Max beats GPT-6 Astra Max on the Intelligence Index vs. cost curve A few other things stand out: 1. At medium, GPT-6 Sol is much cheaper than Sonnet 5.5 at a fairly similar intelligence level. 2. Around the Pareto line, GPT-6 Sol Max and Sonnet 5.5 High are basically neck and neck. 3. GPT-6 Astra Max lands roughly around Sonnet 5.5 XHigh. + Sonnet 5.5 Max is in a league of its own at the top.
  5. · Alex's posts · Alex Getman
    Excerpt
    🚨 Sonnet 5.5 ranks #2 on the Artificial Analysis Intelligence Index, ahead of Fable 5.1. It also beats GPT-6 Sol by 8 points.
  6. · Alex's posts · Alex Getman
    Excerpt
    🚨 Sonnet 5.5 now outputs 30% more tok/s
  7. · Alex's posts · Alex Getman
    Excerpt
    Sonnet 5.5 Max even beats Opus 5.5 Max on Terminal-Bench, while staying close to Opus across the rest. And against GPT Sol, the price/performance gap looks pretty brutal.
  8. · Evidence links · Claude Code · changelog
  9. · Alex's posts · Alex Getman
    Excerpt
    🚨 Sonnet 5.5 benchmarks are out It crushes Sonnet 5, goes toe-to-toe with Opus 5.5, and beats GPT-6 Sol across most shared benchmarks.
  10. · Alex's posts · Alex Getman
    Excerpt
    🚨 Sonnet 5.5 IS OUT!
  11. · Alex's posts · Alex Getman
    Excerpt
    Sonnet 5.5 is launching right now!
  12. · Alex's posts · Alex Getman
    Excerpt
    Claude Sonnet 5.5 is already rolling out in stealth. A lot of users, including free users, are being routed to it. The release is very close.

Evidence links

  • · Catalogue listing · Anthropic API · claude-sonnet-5-5

Alex's take

Signals 4

Alex's posts 4

Specifications

Claude Sonnet 5.5 is a model from Anthropic, released on 28 Sep 2026. The context window is 1,000,000 tokens. The maximum output is 128,000 tokens. Pricing is $2.00 per million input tokens and $10.00 per million output tokens.

Context window
1,000,000
Max output
128,000
Input
text · image
Output
text
Input · USD / 1M tokens
$2.00
Output · USD / 1M tokens
$10.00
Cached input · USD / 1M tokens
$0.10

Questions

What is the context window of Claude Sonnet 5.5?

The context window is 1,000,000 tokens. The maximum output is 128,000 tokens.

How much does Claude Sonnet 5.5 cost?

Pricing is $2.00 per million input tokens and $10.00 per million output tokens. Cached input is $0.10 per million.

When was Claude Sonnet 5.5 released?

On 28 Sep 2026.