The arena · AI model review
Claude Opus 5
by Anthropic
Anthropic's July 2026 Opus refresh: near-Fable 5 intelligence at half the price, same $5/$25 as Opus 4.8
$25/1M out
Official Anthropic API list price for claude-opus-5: $5/1M input, $25/1M output, unchanged from Opus 4.8, single tier with 1M context as default and maximum, 128K max output, prompt caching from 512 tokens. Research-preview Fast mode at $10/$50 (~2.5x faster) is Claude API only. Verified against platform.claude.com (What's new in Opus 5) 2026-07.
Anthropic
1M tokens
$5/1M in
$25/1M out
text, vision
No
What is Claude Opus 5?
Released 2026-07-24 as the direct replacement for Opus 4.8 in Anthropic's Series 5 lineup (Mythos 5, Fable 5, Sonnet 5, Opus 5). API ID claude-opus-5: $5/$25 per 1M tokens (unchanged from Opus 4.8), 1M context as both default and maximum, 128K max output, thinking on by default with a five-level effort scale (low to max). Positioned as near-frontier intelligence at half the price of Fable 5: it actually beats Fable 5 on Frontier-Bench (43.3% vs 33.7%) and GDPval-AA v2 (Elo 1861 vs 1747) while trailing it slightly on SWE-bench Pro (79.2% vs 80.0%). Safety classifiers trigger 85% less often than on Fable 5, and a default fallback mode avoids silent refusal errors.
Claude Opus 5 pros & cons
Pros
- Ranked #1 in composite intelligence across 190 models on Artificial Analysis at launch, and 43.3% on Frontier-Bench v0.1 vs 34.4% for GPT-5.6 Sol and 33.7% for Claude Fable 5
- 3.9x better than GPT-5.6 Sol on ARC-AGI-3 novel reasoning (30.2% vs 7.8%), and Elo 1861 on GDPval-AA v2 economic knowledge work, ahead of Fable 5 (1747)
- 79.2% on SWE-bench Pro, within a point of Fable 5 (80.0%) and 10 points above Opus 4.8 (69.2%), at half Fable's price; Cursor's co-founder calls it 'near Fable 5 intelligence at Opus speed and cost'
- Same $5/$25 pricing as Opus 4.8 with a bigger window: 1M context is now the default and only tier, with 128K max output and prompt caching from 512 tokens
- Dual-use safety classifiers trigger 85% less often than on Fable 5, and the new default fallback mode avoids the silent mid-session refusals that plagued Fable's launch
- Self-verifies its work without being told, handles mid-conversation tool changes (beta) without busting the prompt cache, and ships day one on Claude.ai, the API, Bedrock, Vertex and Microsoft Foundry
Cons
- Notably slow and very verbose: 52.6 output tokens/s and 68 seconds to first token on Artificial Analysis, and it consumed ~100M output tokens during their eval vs a 63M median
- The verbosity is a real-world cost problem: CodeRabbit measured it reading ~50% more and writing ~65% more than reference frontier models per code-review call
- No actual price cut despite the 'cost-efficient' narrative: identical to Opus 4.8 ($5/$25), nearly GPT-5.6 money ($5/$30), and more than 2x comparable Gemini or Grok tiers
- Reviewers describe a 'brilliant but annoying' personality: over-verification, hedging, and occasional refusals of mundane tasks like resolving a merge conflict (Lenny's Newsletter field review)
- Breaking API change for Opus 4.8 migrants: thinking is on by default and cannot be disabled at xhigh or max effort (returns a 400); Fast mode ($10/$50, ~2.5x faster) is API-only, not on Bedrock or Vertex
The arena’s verdict
Claude Opus 5 is the sane default of the Series 5 range: most of Fable 5's intelligence (and more than Fable on Frontier-Bench and GDPval) at exactly half the token price, with classifiers that trigger 85% less often. If you migrated workloads to Fable 5 for capability but resent the bill or the false-positive refusals, move them here; if you are still on Opus 4.8, the upgrade is 10 SWE-bench Pro points for free. The two honest reasons to look elsewhere: latency and verbosity. At 52.6 tokens/s with 68s to first token it is a poor fit for interactive UX, and its token appetite quietly inflates real costs beyond the sticker price, so budget-sensitive high-volume pipelines still belong on Sonnet 5, Gemini or DeepSeek. Keep Fable 5 only for the longest autonomous runs where its slight SWE-bench Pro edge compounds.
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Top Claude Opus 5 alternatives
All alternativesAnthropic's fastest model: about 90% of Sonnet 4.5's coding skill at $1/$5 per 1M tokens, 200K context.
Anthropic's June 2026 Mythos-class flagship: 80.3% on SWE-bench Pro, 11 points clear of every other frontier model
Compare Claude Opus 5 head-to-head
What the crowd says
“The sticker price is unchanged but my invoice is not: it writes essays where Opus 4.8 wrote answers. 68 seconds to first token killed it for our support chat, we went back to Sonnet 5.”
“Fed it a 40-tab financial model with cross-sheet formulas and asked for a scenario deck. It got the edge cases the analysts missed. For document-heavy enterprise work this is the best model I have used.”
“We moved off Fable 5 because the bio classifier kept flagging our genomics tooling. Opus 5 does the same work at half the price and I have not seen a single silent reroute since.”
“Migrated our agents from Opus 4.8 the day it dropped. Same bill, and tasks that used to stall at the planning stage now just finish. The 10-point SWE-bench jump is not marketing, our merge queue feels it.”
Claude Opus 5: frequently asked questions
How much does Claude Opus 5 cost per 1M tokens?
Claude Opus 5 costs $5/1M in per 1M input tokens and $25/1M out per 1M output tokens. Official Anthropic API list price for claude-opus-5: $5/1M input, $25/1M output, unchanged from Opus 4.8, single tier with 1M context as default and maximum, 128K max output, prompt caching from 512 tokens. Research-preview Fast mode at $10/$50 (~2.5x faster) is Claude API only. Verified against platform.claude.com (What's new in Opus 5) 2026-07.