Yeschat

Chat with Claude Opus 4.8 Online

Deep reasoning and long tasks at 1× per message, on the Ultra plan in the YesChat chat.

What is Claude Opus 4.8?

Claude Opus 4.8 is the earlier Opus model on YesChat. Kie.ai's model page describes it as a major upgrade in complex reasoning, agentic coding and professional knowledge work, with stronger long-horizon task execution. On YesChat it is on the Ultra plan at 1×, half the multiplier of Opus 5. Click "Chat with Claude Opus 4.8 in YesChat" to open the YesChat chat with it already selected.

What Claude Opus 4.8 is good for

Complex reasoning

Problems with many conditions, careful comparisons and decisions where you want the reasoning written out.

Long documents and reports

Read a long contract, study or report in agent mode and ask detailed questions about it.

Larger coding tasks

Plan a feature, review code across files, or track down a subtle bug.

Long sessions on Ultra at 1×

On the Ultra plan it gives you Opus-class work while each message counts at 1×.

Which Claude model to choose on YesChat

YesChat offers five Claude models. They differ in depth, in the plan that includes them and in how many credits a message uses. Haiku and Sonnet models are on the Pro plan; Opus models are on the Ultra plan.

Claude Haiku 4.5

Pro plan, 1×. The lightest Claude: quick questions and short tasks where a fast reply matters more than depth. More about Claude Haiku 4.5.

Claude Sonnet 4.6

Pro plan, 1×. The previous Sonnet generation: useful for comparing answers or keeping the model you used before. More about Claude Sonnet 4.6.

Claude Sonnet 5

Pro plan, 1×. The newest Sonnet and the default pick on Pro for writing, analysis and coding. More about Claude Sonnet 5.

Claude Opus 4.8

Ultra plan, 1×. The earlier Opus: deep reasoning and long tasks at half the multiplier of Opus 5.

Claude Opus 5

Ultra plan, 2×. The newest Opus: the hardest multi-step tasks, where follow-through matters most. More about Claude Opus 5.

How to chat with Claude Opus 4.8 online

  • Create a free account

    Sign up for free, no credit card needed. A free account includes 15 messages a day with GPT-5.6 Luna.

  • Choose the Ultra plan

    Claude Opus 4.8 is included from the Ultra plan. Paid plans share one monthly pool of credits for chat, images, video and music.

  • Click "Chat with Claude Opus 4.8 in YesChat" and ask

    Click "Chat with Claude Opus 4.8 in YesChat": the YesChat chat opens with Claude Opus 4.8 already selected. Type your question; upload a file if the task is about a document.

Frequently Asked Questions