Is Claude 4.5 Sonnet or Claude 4.8 Opus cheaper?

For a typical request (10,000 input + 2,000 output tokens), Claude 4.5 Sonnet is cheaper — about 40% less, or roughly $4000 saved per 100,000 requests. Claude 4.5 Sonnet runs $3/$15 per 1M input/output tokens; Claude 4.8 Opus runs $5/$25.

Which has the larger context window?

Claude 4.8 Opus, at 1,000,000 tokens versus 200,000.

How accurate are these token counts?

Claude 4.5 Sonnet: Approximated with cl100k_base — drift typically <2% on English and code. Claude 4.8 Opus: Approximated with cl100k_base — drift typically <2% on English and code. The dollar math itself is exact once the token count is known.

Claude 4.5 Sonnet vs Claude 4.8 Opus: pricing & cost comparison

On input tokens, Claude 4.5 Sonnet is the cheaper of the two — 40% less per million ($3 vs $5). On output, Claude 4.5 Sonnet is 40% cheaper ($15 vs $25) — and since output is usually the dominant cost driver, that gap matters more than it looks.

Side by side

	Claude 4.5 Sonnet	Claude 4.8 Opus
Input / 1M tokens	$3	$5
Output / 1M tokens	$15	$25
Context window	200,000	1,000,000
Token-count accuracy	±2%	±2%
Cost — 10,000 input + 2,000 output tokens	$0.06	$0.1

What a real request costs

Take a representative turn — 10,000 input + 2,000 output tokens. Claude 4.5 Sonnet comes to $0.06, Claude 4.8 Opus to $0.1. Across 100,000 requests that's a $4000 swing in favour of Claude 4.5 Sonnet. To run the numbers on your actual prompt, paste it into the calculator and toggle Compare across all models.

Same vendor — an easy switch

Moving between Claude 4.5 Sonnet and Claude 4.8 Opus is a same-vendor move — one SDK, one tokenizer, so no recalibration. That makes this a straight cost/quality call: send the routine bulk of traffic to Claude 4.5 Sonnet ($3/$15 per 1M) and reserve Claude 4.8 Opus for the requests that visibly need its extra headroom. On the worked example above that split is worth about 40% per request — small per call, real money once you multiply by volume.

See the full breakdown on the dedicated pages for Claude 4.5 Sonnet and Claude 4.8 Opus.

FAQ

Is Claude 4.5 Sonnet or Claude 4.8 Opus cheaper?: For a typical request (10,000 input + 2,000 output tokens), Claude 4.5 Sonnet is cheaper — about 40% less, or roughly $4000 saved per 100,000 requests. Claude 4.5 Sonnet runs $3/$15 per 1M input/output tokens; Claude 4.8 Opus runs $5/$25.
Which has the larger context window?: Claude 4.8 Opus, at 1,000,000 tokens versus 200,000.
How accurate are these token counts?: Claude 4.5 Sonnet: Approximated with cl100k_base — drift typically <2% on English and code. Claude 4.8 Opus: Approximated with cl100k_base — drift typically <2% on English and code. The dollar math itself is exact once the token count is known.

Both prices are computed from tokenmath's verified pricing table. Rates sourced from www.anthropic.com and platform.claude.com, verified 2026-07-06. Vendor pricing changes often — confirm before you commit.