Claude Opus 5 Launch: Near Fable 5 at Half the Price
Anthropic shipped Claude Opus 5 on July 24, 2026: near Fable 5 intelligence at half the price, $5/$25 like Opus 4.8, Frontier-Bench SOTA 43.3%, ARC-AGI-3 30.2%.
Claude Opus 5 is out. On July 24, 2026, Anthropic ended weeks of Honeycomb / Thursday rumor coverage with a public ship: a thoughtful, proactive Opus-class model that “comes close to the frontier intelligence of Fable 5 at half the price.”
The official announcement thread put the pitch in one line — then stacked coding SOTA claims, cost-efficiency charts, ARC-AGI-3, alignment, and cyber safeguards. This explainx.ai guide is the builder-facing decode: what the numbers actually say, where Opus 5 wins vs Fable 5, and how to choose effort / Fast mode without burning weekly credits.
TL;DR — What People Are Asking
Question
Answer
Available?
Yes — July 24, 2026 · claude-opus-5
Price?
$5 / $25 per M tokens (same as Opus 4.8)
vs Fable 5?
Near frontier IQ · ~half the price · often better $/task
Max / Pro?
Default on Max · strongest on Pro
Fast mode?
~2.5× speed · 2× base price
Coding SOTA?
Frontier-Bench 43.3% (vs Fable 33.7%)
Novel problems?
ARC-AGI-3 30.2% (~3× next best shown)
Alignment?
Lowest misalignment audit score (2.30)
Cyber?
Strong vuln ID · behind Mythos on exploits (by design)
The announcement clip from Anthropic’s @claudeai X thread — hosted locally so it loads without X embeds:
Anthropic’s news page also ships interactive demos Opus 5 built — a wind tunnel and a 3D cell:
Official Anthropic demo — Opus 5 visualizes aerodynamic flow.
Official Anthropic demo — interactive cell artifact from Opus 5.
The Product Pitch in Plain English
Opus 5 is not “Fable but free.” It is Anthropic’s bet that most daily agent work should run on a model that:
Matches or beats prior Opus on coding, knowledge work, computer use, and business workflows
Approaches Fable on many agentic coding / Cursor-style benches at half the $/task
Stays cheaper and more available than Mythos-class Fable for subscription defaults
Ships with stronger alignment and cyber classifiers that favor finding bugs over writing exploits
Pricing is deliberately boring: $5 input / $25 output per million tokens — identical to Opus 4.8. The upgrade is capability density per dollar, not a new SKU tax.
Benchmark Snapshot (Anthropic-Published)
Treat these as vendor evaluations — useful for ranking Anthropic’s own stack and for comparing effort ladders, not as a substitute for your private harness. Numbers below come from Anthropic’s launch materials and the charts they posted with the Opus 5 announcement.
Benchmark
Opus 5
Fable 5
Opus 4.8
GPT-5.6 Sol
Agentic terminal coding (Frontier-Bench v0.1)
43.3%
33.7%
21.1%
34.4%
Knowledge work (GDPval-AA v2)
1861
1747
1593
1736
Novel problem-solving (ARC-AGI-3)
30.2%
—
1.5%
7.8%
Agentic search (BrowseComp)
90.8%
87.4%
84.3%
90.4%
HLE — no tools
56.3%
56.5%
49.8%
—
HLE — with tools
64.7%
63.9%
57.9%
—
Computer use (OSWorld 2.0)
70.6%
66.1%
55.7%
62.6%
Agentic coding (DeepSWE v1.1)
68.8%
69.7%
59.0%
72.7%
Agentic coding (FrontierCode Main)
53.4%
53.5%
46.5%
47.5%
Business workflows (AutomationBench)
26.0%
17.4%
17.0%
18.1%
Legal (held-out)
11.7%
13.3%
10.4%
2.5%
Health (HealthBench Professional)
59.8%
66.0% (Mythos 5)
57.4%
60.5%
Biology hard (BioMysteryBench)
49.4%
46.5%
42.4%
—
Biology human-solved
90.1%
89.0% (Mythos 5)
88.5%
—
What the table actually implies
Opus 5 owns the “daily agent” cluster: Frontier-Bench, GDPval, ARC-AGI-3, BrowseComp, OSWorld, AutomationBench. That is terminal coding, knowledge work, novel puzzles, search, desktop control, and multi-step business flows.
Fable / Mythos still own specialist peaks: Legal, Health, and (below) cyber exploitation. DeepSWE still favors GPT-5.6 Sol in this table. FrontierCode Main is a coin flip with Fable.
If your workload is “ship a product in a large repo,” Opus 5 is the new default story. If your workload is “Mythos-tier science / cyber red team,” you still need the higher tier — and Anthropic’s safeguards intentionally keep Opus 5 behind Mythos on exploit development.
Effort Ladders — Why “Half the Price” Is a Chart, Not a Slogan
Anthropic’s launch charts plot score vs cost per task across effort ladders (low → medium → high → xhigh → max). That is the same model vs effort frame Lydia Hallie documented for Claude Code — capability is the weights; effort is how hard those weights work.
Agentic terminal coding — Frontier-Bench v0.1
Opus 5 peaks near 43–44% around the mid-teens USD per attempt, while Fable 5’s ladder tops out near 33.7% at nearly $27. Opus 4.8 never clears ~19% on this internal mini-SWE-agent run. GPT-5.6 Sol climbs from cheap/low scores into the high 30s — competitive on cost at low effort, not at the Opus 5 ceiling.
Computer use — OSWorld 2.0
Opus 5’s low-effort point (~60% near $8) already beats most competitors’ expensive peaks. Max effort lands around 70.6% near $25. Fable’s ladder is higher-cost for lower peaks; Sol spans a wide cheap-to-mid range but caps below Opus 5.
Business workflows — AutomationBench
This is the clearest “top-left” win: Opus 5 sits at higher pass rates (~22–26%) for lower cost (~$0.75–$1.25) than Fable / Opus 4.8 clusters (~16–17.5% at $1.20–$2.40). Sol can be cheaper at low effort but never catches Opus 5’s pass rate.
Multidisciplinary reasoning — Humanity’s Last Exam (with tools)
Opus 5 reaches ~65% near $2, while Fable needs ~$4.50 to hit ~64%. Opus 4.8 plateaus near 58%. Efficiency, not just peak IQ.
Novel problem-solving — ARC-AGI-3
Opus 5’s ~30% at just over $20k total eval cost is the headline step-change. Opus 4.8 sits near 1–2%; Sol’s effort ladder tops near 8% at higher total cost. This is the chart Anthropic used for “three times the next best model.”
Alignment and Cyber — What “Safeguards” Mean in Practice
Lower is better on Anthropic’s automated behavioral audit. Opus 5 at 2.30 beats Opus 4.8 (2.85), Mythos 5 (2.81), and Sonnet 5 (3.35). Anthropic’s claim: lowest rates of reckless / deceptive behavior and strongest Constitution adherence among recent models.
On OSS-Fuzz, Opus 5 nearly matches Mythos 5 on vulnerability identification (~79–80% vs Opus 4.8’s 61.5%) but trails badly on exploitation success (Opus 5 4 vs Mythos 13; Opus 4.8 0). That gap is intentional: classifiers allow finding issues in source while blocking binary scanning, pen-testing, and exploit generation for most users. Flagged traffic can fall back to Opus 4.8; CVP customers get a less-restricted variant.
explainx.ai’s read: Opus 5 is the model Anthropic wants defenders and product teams on daily — not the model they want unconstrained on red-team exploit loops. For dual-use context, see our AI cyber guardrails coverage — without turning this post into an exploit how-to.
Also update your context stack. Anthropic’s Claude Code team says they removed over 80% of the system prompt for Opus 5 / Fable 5 with no measurable coding-eval loss — see our companion on Claude 5 context engineering and the earlier thin prompts / thick artifacts frame.
Getting Started Today
bash
# Claude Code
/model claude-opus-5
# API model string
claude-opus-5
Benchmarks and pricing as published by Anthropic on July 24, 2026. Re-verify model IDs, Fast-mode billing, and classifier fallbacks on anthropic.com / platform.claude.com before production commits.
