Claude Opus 5.5 vs Claude Sonnet 5.5

Claude Opus 5.5 and Claude Sonnet 5.5 at a glance

Claude Opus 5.5 is an Anthropic model available in Quad Chat, with up to 1M tokens of context, image input, tool calling and adjustable reasoning. Claude Sonnet 5.5 is an Anthropic model available in Quad Chat, with up to 1M tokens of context, image input, tool calling and adjustable reasoning. This page compares specifications and plan availability from the Quad Chat model catalog. It does not publish benchmark scores, because quality depends on your task; the quickest fair test is to send the same prompt to both models in one Quad Chat conversation. Each family has a single variant, so the head-to-head compares them directly.

Claude Opus 5.5 vs Claude Sonnet 5.5

Top variant of each family, side by side. Lab: Claude Opus 5.5 Anthropic, Claude Sonnet 5.5 Anthropic. Plan needed: Claude Opus 5.5 Ultra ($40/month), Claude Sonnet 5.5 Pro ($15/month). Context window: Claude Opus 5.5 1M tokens, Claude Sonnet 5.5 1M tokens. Max output: Claude Opus 5.5 128K tokens, Claude Sonnet 5.5 128K tokens. API input price: Claude Opus 5.5 $4.00 per 1M, Claude Sonnet 5.5 $2.00 per 1M. API output price: Claude Opus 5.5 $20.00 per 1M, Claude Sonnet 5.5 $10.00 per 1M. Image input: Claude Opus 5.5 Yes, Claude Sonnet 5.5 Yes. Tool calling: Claude Opus 5.5 Yes, Claude Sonnet 5.5 Yes. Reasoning: Claude Opus 5.5 Yes, adjustable (low, medium, high, xhigh, max), Claude Sonnet 5.5 Yes, adjustable (low, medium, high, xhigh, max). Privacy lane: Claude Opus 5.5 Private Lane (Zero Data Retention), Claude Sonnet 5.5 Private Lane (Zero Data Retention).

Choose Claude Opus 5.5 or Claude Sonnet 5.5

Each point below comes from a real difference in the catalog data. Choose Claude Opus 5.5 if: The catalog shows no spec advantage for Claude Opus 5.5 in this pairing, so choose it after running your own prompts on both. Choose Claude Sonnet 5.5 if: You want the lower API list price at the top tier: Claude Sonnet 5.5 lists at $2.00 in / $10.00 out against $4.00 in / $20.00 out for Claude Opus 5.5, about 2.0× less per output token. You want to start on a lower plan: Claude Sonnet 5.5 has a variant on the Pro ($15/month) plan, while Claude Opus 5.5 starts at Ultra ($40/month). You want top-tier access for less: Claude Sonnet 5.5 needs Pro ($15/month), while Claude Opus 5.5 needs Ultra ($40/month). Their context windows are within 10% of each other (1M and 1M tokens). Their longest replies are within 10% of each other (128K and 128K tokens). You do not have to choose: Quad Chat lets you switch between Claude Opus 5.5 and Claude Sonnet 5.5 in the same conversation, or ask both at once and compare the answers.

Every Claude Opus 5.5 and Claude Sonnet 5.5 variant

All selectable variants of both families. Click a header to sort. Claude Opus 5.5: Claude Opus 5.5 (Ultra). Claude Sonnet 5.5: Claude Sonnet 5.5 (Pro).

Frequently asked questions

Is Claude Opus 5.5 or Claude Sonnet 5.5 cheaper?

At provider list prices, Claude Sonnet 5.5 is cheaper at the top tier ($2.00 in / $10.00 out against $4.00 in / $20.00 out per million tokens). API prices are the model provider's list prices per million tokens, shown for comparison only. Quad Chat plans have a flat monthly price and draw usage from shared credits, so you are not billed per token.

Which has the larger context window, Claude Opus 5.5 or Claude Sonnet 5.5?

They match: both reach 1M tokens. Files, pasted text and earlier messages all count toward the window.

Which Quad Chat plan do I need for Claude Opus 5.5 and Claude Sonnet 5.5?

Claude Opus 5.5 needs the Ultra ($40/month) plan. Claude Sonnet 5.5 needs the Pro ($15/month) plan. Plans are cumulative, and every plan shares one monthly credit balance (100 on Free up to 25,000 on Max).

Do Claude Opus 5.5 and Claude Sonnet 5.5 support images, tools and reasoning?

Claude Opus 5.5: image input yes, tool calling yes, reasoning yes. Claude Sonnet 5.5: image input yes, tool calling yes, reasoning yes. Other variants in each family can differ, as the variant table shows.

Can I use Claude Opus 5.5 and Claude Sonnet 5.5 in the same chat?

Yes. In Quad Chat you can switch between models mid-conversation without losing your files or context, or send one prompt to both and compare the answers side by side, which is the most reliable way to decide between them for your own work. Side-by-side comparison is included on every plan.

Is Claude Opus 5.5 or Claude Sonnet 5.5 more private in Quad Chat?

Both top variants run on the Private Lane, routed to providers under Zero Data Retention terms. Quad Chat does not train models on your conversations either way.