Real head-to-head · same prompt, one shot
Grok vs Claude Opus 5.5
Snappy + real-time — the X-native model. vs Anthropic's Opus 5.5 — benched on all 50 one-shot builds, every game playtested.
Head-to-head verdict: Grok wins 24–17 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 Grok and Claude Opus 5.5, 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.
Grok · Used for real-time content workflows where the model needs current X timeline context. Standalone bench scoring pending.
Claude Opus 5.5 · Benched on all 50 GoldieBench tasks via a Claude subscription: one-shot builds, real renders, pixel-diff playtests on every game, then vision-judged.
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 = 🥉).
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Grok
Claude Opus 5.5
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Where Grok beat Claude Opus 5.5
The tasks where I gave Grok a higher 0–10 score on the same prompt — with the actual commentary from my source guides.
Twilightvale
Game
Grok 9.5
·
Claude Opus 5.5 5.5
(+4.0)
· winner · open world depth
What I saw: Twilight Vale — 3D open-world RPG with hand-crafted village, NPCs, combat, day/night, weather, inventory. 38KB — densest build of the bench, edges out Fusion's 32KB.
Rpg
Game
Grok 9.0
·
Claude Opus 5.5 5.5
(+3.5)
· winner · top-down RPG
What I saw: 35KB top-down RPG with tilemap, walkable terrain, NPCs, combat, HP/MP UI, inventory. Beats Fusion's lighter 26KB attempt on density.
Doom
Game
Grok 8.5
·
Claude Opus 5.5 5.8
(+2.7)
What I saw: Doom-style FPS with sprite enemies, gun + muzzle flash + ammo/health HUD, textures, pointer-lock mouse-look. 22KB.
Neonblaster
Game
Grok 8.5
·
Claude Opus 5.5 5.8
(+2.7)
What I saw: Juicy 2D arcade space shooter — waves, bosses, power-ups, screen-shake, synth music via Web Audio, neon particles. 24KB.
Voxelcraft
Game
Grok 8.5
·
Claude Opus 5.5 5.8
(+2.7)
What I saw: Minecraft-style voxel sandbox, fly + break + place, day/night cycle, hotbar. 22KB.
Where Claude Opus 5.5 beat Grok
The tasks where I gave Claude Opus 5.5 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.
Aurora
Visual
Claude Opus 5.5 8.4
·
Grok 7.0
(+1.4)
What I saw: Lovely low-poly valley: layered shader aurora curtains, snowy peaks, a glowing cabin and a mirror lake reflection, plus palette and substorm controls. The foreground snow is a flat, overexposed cyan band that eats the bottom third of the frame.
Matrix
Visual
Claude Opus 5.5 8.3
·
Grok 7.0
(+1.3)
What I saw: Dense, authentic green katakana rain with real depth layering, glow and bright lead glyphs, plus parallax, fly, ripple and colour controls. The capture shows the rain paused, and the title and stats panels sit over the rain.
Fluid
Sim
Claude Opus 5.5 8.5
·
Grok 7.5
(+1.0)
What I saw: Real GPU Navier-Stokes with vorticity: vivid curling dye plumes and a dense advected particle layer read as a proper swirling fluid, and the control pills are tidy. The stats line still says a stale 'starting…', and the look is a little busy next to the field's 9.0 best.
Blackhole
Sim
Claude Opus 5.5 8.8
·
Grok 8.0
(+0.8)
What I saw: Striking real ray-marched Schwarzschild lensing: the Einstein ring bends over the top, the photon ring is thin and bright, the disk is Doppler-beamed and the streaked starfield looks good; controls are clean. Right up with the field's best, though the disk's banded ripple texture…
Plasma
Visual
Claude Opus 5.5 8.2
·
Grok 7.5
(+0.7)
What I saw: Smooth, hypnotic GPU plasma with 8 palette swatches, speed/scale/warp sliders and a visible click ripple, all in tidy minimal UI. It is on-brief and polished but not quite the field-best wow.
Strengths & weaknesses I logged
Grok
Strengths
- Real-time access to X timeline data — unique signal no other model has
- Snappy latency on shorter prompts
- 256K context window keeps pace with the open-weights field
Trade-offs
- 13 demos on the bench but zero have curated 0–10 verdicts yet — currently unranked
- API access is gated behind X Premium, awkward for backend agent loops
Claude Opus 5.5
Strengths
- Frontier-class coding + agentic reasoning (Claude 5 family)
- 1M-token context — reads an entire codebase in one call
- All 50 one-shot builds rendered with zero console errors; all 23 games passed the input playtest
Trade-offs
- Premium pricing ($4/$20 per M) — route the everyday 90% to cheaper lanes
- One-shot builds can still ship logic bugs (e.g. a doom kill counter that miscounts)
Pricing & context — the spec sheet
| Spec | Grok | Claude Opus 5.5 |
|---|---|---|
| Vendor | xAI | Anthropic |
| Context window | 256,000 tokens | 1,000,000 tokens |
| Price | Subscription via X Premium | $4 / $20 per M |
| Pricing detail | Bundled with X (Twitter) Premium subscription — no per-token bill for end users, no individual API pricing for the chat product. | Anthropic's Opus 5.5 — 1M-token context, listed at $4 input / $20 output per million tokens. Benched through a Claude subscription; game tasks use our skill-infused AAA build prompts. |
| Release | 2026-04 | 2026-09 |
| Bench coverage | 43/47 scored · avg 8.09/10 | 50/50 scored · avg 7.57/10 |
The verdict — which should you pick?
Across 43 scored shared tasks, Grok averaged 8.09/10, beating Claude Opus 5.5's 7.60/10 by 0.49 points. Pick Grok 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 Grok and Claude Opus 5.5 both into the Agent Operating System and dispatch each from the kanban by task type — workflows that need live x / twitter context → Grok, hardest agentic builds → Claude Opus 5.5. That's the same setup I run for the 4,000+ founders inside the AI Profit Boardroom.
FAQ — Grok vs Claude Opus 5.5
Which is better, Grok or Claude Opus 5.5?
On Goldie Bench, Grok averages 8.09/10 across the shared tasks, with 5 gold, 1 silver, 1 bronze overall. Claude Opus 5.5 averages 7.60/10, with 0 gold, 0 silver, 1 bronze. Grok wins the head-to-head 24–17.
How much does Grok cost vs Claude Opus 5.5?
Grok: Bundled with X (Twitter) Premium subscription — no per-token bill for end users, no individual API pricing for the chat product. Claude Opus 5.5: Anthropic's Opus 5.5 — 1M-token context, listed at $4 input / $20 output per million tokens. Benched through a Claude subscription; game tasks use our skill-infused AAA build prompts.
What's the context window for Grok vs Claude Opus 5.5?
Grok has a 256,000 tokens context window. Claude Opus 5.5 has a 1,000,000 tokens context window.
When should I pick Grok over Claude Opus 5.5?
Pick Grok for: Workflows that need live X / Twitter context; Snappy prompts where latency matters; Researchers comparing X-native models against the rest of the field. The trade-off is the weaknesses we logged on the bench: 13 demos on the bench but zero have curated 0–10 verdicts yet — currently unranked; API access is gated behind X Premium, awkward for backend agent loops.
When should I pick Claude Opus 5.5 over Grok?
Pick Claude Opus 5.5 for: Hardest agentic builds; Whole-repo reasoning; Frontier one-shots. The trade-off is the weaknesses we logged on the bench: Premium pricing ($4/$20 per M) — route the everyday 90% to cheaper lanes; One-shot builds can still ship logic bugs (e.g. a doom kill counter that miscounts).
How does Goldie Bench score Grok vs Claude Opus 5.5?
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:
Grok vs Fusion Claude Opus 5.5 vs Fusion Grok vs Claude Opus 5 Claude Opus 5.5 vs Claude Opus 5 Grok vs Hermes MoA Claude Opus 5.5 vs Hermes MoA Grok vs GPT-5.6 Sol Claude Opus 5.5 vs GPT-5.6 SolFull model pages: Grok · Claude Opus 5.5 · 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