Real head-to-head · same prompt, one shot
Claude Opus 5 vs Opus 4.8
The new Anthropic flagship — benched on all 45 one-shot builds the day it landed. vs The reasoning king — deepest thinking, premium price.
Head-to-head verdict: Claude Opus 5 wins 36–9 with 2 ties.
What I tested — same prompt, two models
I run the same fixed prompt set through every new model the day it drops — same string, one shot, single HTML file out — and I score the result 0–10 on whether it ran, how close it hit the brief, and how good it looked. Below is what came out when I gave the exact same prompts to Claude Opus 5 and Opus 4.8, side by side, on 47 shared tasks inside the Agent Operating System.
Both models were given identical prompts inside the Agent Operating System — no help, no iteration, no "best of N" tricks. I run each prompt once, save the HTML file the model produces, and score it 0–10 on whether it ran, how close it hit the brief, and how good it looked. The scoring is mine. The verdicts below are pulled from my source comparison guides at agentos.guide where I publish every score and the reasoning behind it.
Claude Opus 5 · Benched on all 45 GoldieBench tasks via API on release day, incremental deploys as scores landed.
Opus 4.8 · The default when the build has to ship on the first prompt — Opus is the safety net inside Agent OS for hard one-shots.
Side-by-side on 50 shared tasks
Click any cell to play that model's actual one-shot attempt. Medals are derived from my 0–10 scores per task (highest = 🥇, second = 🥈, third = 🥉).
Task ↓
Claude Opus 5
Opus 4.8
Game
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Page
Where Claude Opus 5 beat Opus 4.8
The tasks where I gave Claude Opus 5 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.
Webos
Page
Claude Opus 5 8.7
·
Opus 4.8 5.5
(+3.2)
· 3D glass desktop
What I saw: Stunning execution: glassmorphic windows with mac-style traffic-light controls, three live apps stacked (Notes/Paint/Terminal), functional dock, menubar clock, and a gorgeous animated Three.js background of shaded/wireframe solids — clearly matches or beats the field's best. Only…
Aurora
Visual
Claude Opus 5 8.6
·
Opus 4.8 6.0
(+2.6)
· cinematic aurora scene
What I saw: Gorgeous WebGL curtains with realistic vertical streaks, layered mountains, starfield and water reflection make this a full cinematic scene; polished palette switcher and typography plus reflection depth push it past the field's best.
Crypt
Game
Claude Opus 5 8.4
·
Opus 4.8 6.0
(+2.4)
What I saw: Strong torch-lit crypt with a menacing skeleton enemy front-and-center, weapon in hand, full HUD (health/stamina/torch, minimap, kills/depth/foes) and atmospheric banner — clearly a combat-ready dungeon crawler. Held just short of the top by the heavy red damage-vignette washing …
Fireworks
Visual
Claude Opus 5 9.0
·
Opus 4.8 7.0
(+2.0)
· harbour firework spectacular
What I saw: Stunning multi-type bursts (rings, peonies, chrysanthemums, willows) over a beautifully lit skyline with reflections, moon, and stars; rich UI with auto/finale/sound controls and live stats make it a clear task winner. Only minor concern is the 22fps under heavy load, but visuall…
Nordiccrypt
Game
Claude Opus 5 8.0
·
Opus 4.8 6.0
(+2.0)
What I saw: Strong first-person crypt crawler with a clear enemy (Crypt Shade with health bar) approaching, first-person axe viewmodel, HUD with health/vigor/kills/minimap, and a torch-lit chandelier — combat is present and shippable. Weak points: the scene reads as dim beige boxes rather th…
Where Opus 4.8 beat Claude Opus 5
The tasks where I gave Opus 4.8 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.
Arcade
Game
Opus 4.8 8.5
·
Claude Opus 5 6.5
(+2.0)
· winner · game-feel
What I saw: All three shipped a genuinely juicy game. Opus's breakout had the most game-feel — particle bursts and a live combo. Kimi's breakout was clean and solid. GLM went its own way with fullscreen neon asteroids. The closest of the practical five.
Doom
Game
Opus 4.8 8.5
·
Claude Opus 5 6.8
(+1.7)
· winner · game-feel
What I saw: All three are real, playable shooters. Opus drops you in a corridor with an imp dead ahead — gun, crosshair and HUD framed like a screenshot. Kimi matches it: a monster down a textured hall, health, ammo, minimap. GLM ships a gorgeous 'HAZARD PROTOCOL' title screen with a working…
Neoncity
Game
Opus 4.8 8.5
·
Claude Opus 5 7.4
(+1.1)
What I saw: GLM's is the most cinematic — neon towers, a setting sun, Japanese signage and a flight HUD, like a frame from a film. Opus's is a clean canyon of lit skyscrapers racing to a vanishing point. Kimi leaned into the synthwave sun and grid more than the city itself. GLM wins the skyline.
Neonblaster
Game
Opus 4.8 7.5
·
Claude Opus 5 6.8
(+0.7)
What I saw: 16KB · plays clean · audio, input
Landing
Page
Opus 4.8 9.0
·
Claude Opus 5 8.4
(+0.6)
· tie · top
What I saw: Funniest result of the lot: GLM and Opus independently produced near-identical premium 'Introducing Nova 1 — Intelligence, reimagined / distilled' keynote pages — gradient hero, full nav, pricing tiers. A dead heat. Kimi's was a plainer set of feature cards.
Strengths & weaknesses I logged
Claude Opus 5
Strengths
- Frontier-class coding + agentic reasoning (Claude 5 family)
- 1M-token context — reads an entire codebase in one call
- Benched here with skill-infused game prompts the day of release
Trade-offs
- Premium pricing ($5/$25 per M) — route the everyday 90% to cheaper lanes
- Reasoning-by-default eats token budgets unless tuned per call
Opus 4.8
Strengths
- Most consistent across the Goldie Bench bench — no weak build, 8.46/10 average
- Deepest one-shot reasoning, especially on game-feel and physics
- Extended thinking mode handles up to 1M tokens of context
Trade-offs
- 5–10× the per-token cost of every other model on the bench
- Less flair on cinematic visuals than GLM-5.2 — playing it safer wins on accuracy, costs you on showpiece moments
Pricing & context — the spec sheet
| Spec | Claude Opus 5 | Opus 4.8 |
|---|---|---|
| Vendor | Anthropic | Anthropic |
| Context window | 1,000,000 tokens | 200,000 tokens (1M with extended thinking) |
| Price | $5 / $25 per M | $15 / $75 per M tokens |
| Pricing detail | Anthropic's brand-new flagship — the first Opus of the Claude 5 family, with a 1M-token context window. Benched via API the day it dropped; game tasks use our skill-infused AAA build prompts. | Premium pricing via the Anthropic API: $15 per million input tokens, $75 per million output tokens. Extended thinking is included but adds latency. |
| Release | 2026-07 | 2026-05 |
| Bench coverage | 50/50 scored · avg 8.27/10 | 47/47 scored · avg 7.51/10 |
The verdict — which should you pick?
Across 47 scored shared tasks, Claude Opus 5 averaged 8.29/10, beating Opus 4.8's 7.51/10 by 0.77 points. Pick Claude Opus 5 when the build has to ship on the first prompt and you can afford the trade-offs in the comparison below.
If you only run one of these inside your stack, the head-to-head average above is the call. If you can run both, my honest play is to wire Claude Opus 5 and Opus 4.8 both into the Agent Operating System and dispatch each from the kanban by task type — hardest agentic builds → Claude Opus 5, mission-critical one-shot builds where 'has to work the first time' matters → Opus 4.8. That's the same setup I run for the 4,000+ founders inside the AI Profit Boardroom.
FAQ — Claude Opus 5 vs Opus 4.8
Which is better, Claude Opus 5 or Opus 4.8?
On Goldie Bench, Claude Opus 5 averages 8.29/10 across the shared tasks, with 13 gold, 7 silver, 5 bronze overall. Opus 4.8 averages 7.51/10, with 3 gold, 1 silver, 1 bronze. Claude Opus 5 wins the head-to-head 36–9.
How much does Claude Opus 5 cost vs Opus 4.8?
Claude Opus 5: Anthropic's brand-new flagship — the first Opus of the Claude 5 family, with a 1M-token context window. Benched via API the day it dropped; game tasks use our skill-infused AAA build prompts. Opus 4.8: Premium pricing via the Anthropic API: $15 per million input tokens, $75 per million output tokens. Extended thinking is included but adds latency.
What's the context window for Claude Opus 5 vs Opus 4.8?
Claude Opus 5 has a 1,000,000 tokens context window. Opus 4.8 has a 200,000 tokens (1M with extended thinking) context window.
When should I pick Claude Opus 5 over Opus 4.8?
Pick Claude Opus 5 for: Hardest agentic builds; Whole-repo reasoning; Frontier one-shots. The trade-off is the weaknesses we logged on the bench: Premium pricing ($5/$25 per M) — route the everyday 90% to cheaper lanes; Reasoning-by-default eats token budgets unless tuned per call.
When should I pick Opus 4.8 over Claude Opus 5?
Pick Opus 4.8 for: Mission-critical one-shot builds where 'has to work the first time' matters; Hard reasoning tasks (planning, multi-step) where you'll pay for the depth; Anything where vendor reliability beats the per-token bill. The trade-off is the weaknesses we logged on the bench: 5–10× the per-token cost of every other model on the bench; Less flair on cinematic visuals than GLM-5.2 — playing it safer wins on accuracy, costs you on showpiece moments.
How does Goldie Bench score Claude Opus 5 vs Opus 4.8?
Every demo on this page was built by Julian Goldie inside the Agent Operating System — same fixed prompt for both models, one shot, single HTML file out. Each result gets a 0–10 score on whether it ran, how close it hit the brief, and how good it looked. The highest score on each task gets gold; second gets silver; third gets bronze. See methodology for full provenance.
Related comparisons
Other head-to-heads using the same scoring system:
Claude Opus 5 vs Fusion Opus 4.8 vs Fusion Claude Opus 5 vs Hermes MoA Opus 4.8 vs Hermes MoA Claude Opus 5 vs GPT-5.6 Sol Opus 4.8 vs GPT-5.6 Sol Claude Opus 5 vs Claude Fable 5 Opus 4.8 vs Claude Fable 5Full model pages: Claude Opus 5 · Opus 4.8 · back to the leaderboard
The same stack Julian uses
Run this stack yourself.
Every demo on this bench was built inside the Agent Operating System — one prompt, one shot, single HTML file out. The Agent OS, the prompts, the templates, the weekly walkthroughs and 4,000+ founders shipping with it every day all live inside the AI Profit Boardroom.
4,000+founders
258documented wins
38countries
$59/momonthly