How We Tested 120 Claude Prompt Codes
We ran every known Claude prompt code through the same test: give Claude a moderately complex task (write a marketing email, debug a function, analyze a dataset) with and without each code. Then we scored the difference.
Most codes? Cosmetic. They change formatting — bullet points vs paragraphs, longer vs shorter. About 70% of all prompt codes fall into this bucket.
But 15 codes consistently shifted Claude's actual reasoning, depth, or approach. These are the ones worth memorizing.
The Ranking: 15 Best Claude Prompt Codes
#1: /deepthink
What it does: Forces Claude to reason through every layer of a problem before producing an answer.
When to use it: Complex decisions, multi-step problems, anything where the first answer is usually too shallow.
Example: /deepthink What are the second-order effects of raising our SaaS pricing by 40%?
Without it, Claude gives you a list. With it, Claude walks through customer psychology, churn modeling, competitive positioning, and revenue math before concluding.
Impact score: 9.5/10
#2: BEASTMODE
What it does: Pushes output quality to the absolute maximum. Claude writes longer, more detailed, more nuanced responses.
When to use it: Final drafts, important deliverables, anything where you want Claude's best effort.
Example: BEASTMODE Write the technical architecture doc for our payment processing microservice.
Impact score: 9.2/10
#3: OODA
What it does: Applies the Observe-Orient-Decide-Act military decision framework to any problem.
When to use it: Strategic decisions, competitive analysis, crisis response planning.
Example: OODA Our biggest competitor just launched a free tier. What do we do?
Claude breaks the situation into four phases and gives you actionable next steps, not just analysis.
Impact score: 9.0/10
#4: /ghost
What it does: Rewrites text so it's indistinguishable from human writing. Strips AI patterns — em-dashes, "Furthermore," "It's worth noting," etc.
When to use it: Blog posts, emails, LinkedIn posts, anything public-facing.
Example: /ghost Rewrite this email so no one can tell AI helped.
Impact score: 8.8/10
#5: L99
What it does: Pushes response depth to the maximum level. Think of it as a "detail dial" turned to 99.
When to use it: Research tasks, deep technical explanations, comprehensive analyses.
Example: L99 Explain how transformer attention mechanisms actually work.
Impact score: 8.7/10
#6: /autoprompt
What it does: Takes your rough idea and builds the perfect prompt for it. Meta-prompting.
When to use it: When you know what you want but can't articulate it precisely.
Example: /autoprompt I need Claude to help me plan a product launch
Claude generates a detailed, structured prompt you can then use — often 10x better than what you'd write yourself.
Impact score: 8.5/10
#7: INVERT
What it does: Solves problems by thinking backwards. Instead of "how do we succeed," it asks "how would we guarantee failure?" then inverts.
When to use it: Strategy, risk assessment, product planning.
Example: INVERT How do we make our onboarding so good that nobody churns in the first week?
Impact score: 8.3/10
#8: /blindspots
What it does: Identifies what you're missing, not what you already know.
When to use it: After you've drafted a plan, strategy, or document and want a second opinion.
Example: /blindspots Here's my go-to-market plan: [paste plan]. What am I not seeing?
Impact score: 8.2/10
#9: SENTINEL
What it does: Reviews everything for errors, risks, and missed details. Quality assurance mode.
When to use it: Before shipping code, sending important emails, or publishing content.
Example: SENTINEL Review this pull request for security issues, edge cases, and logic errors.
Impact score: 8.0/10
#10: CEOMODE
What it does: Frames every response through high-stakes business decision making. Cuts fluff, focuses on leverage and ROI.
When to use it: Business strategy, resource allocation, tough calls.
Example: CEOMODE We have $50K and 3 months. What's the highest-ROI move for our startup?
Impact score: 7.8/10
#11: /chain
What it does: Runs multiple prompts in sequence, feeding each output into the next.
When to use it: Complex workflows — research > analysis > recommendations > action plan.
Example: /chain First research the market, then analyze competitors, then recommend positioning.
Impact score: 7.6/10
#12: PERSONA
What it does: Makes Claude respond as a specific expert — lawyer, CFO, marketing director, etc.
When to use it: When you need domain-specific framing, not generic advice.
Example: PERSONA Act as a senior tax attorney. Review this LLC structure.
Impact score: 7.5/10
#13: /debug
What it does: Shifts Claude into systematic bug-finding mode. It doesn't just fix — it explains root cause.
When to use it: Any code that's not working and you can't figure out why.
Example: /debug This function returns undefined instead of the user object. [paste code]
Impact score: 7.3/10
#14: ARCHITECT
What it does: Designs system structure before writing any code. Big picture first, implementation second.
When to use it: Starting new projects, refactoring large codebases, system design interviews.
Example: ARCHITECT Design the backend for a real-time collaboration tool like Figma.
Impact score: 7.2/10
#15: /nofilter
What it does: Gives you Claude's most direct, unfiltered assessment. Drops the diplomatic hedging.
When to use it: When you want honest feedback, not polite encouragement.
Example: /nofilter Is this startup idea actually good or am I fooling myself?
Impact score: 7.0/10
Codes That Didn't Make the Cut
Some popular codes that sound impressive but tested as mostly formatting changes:
/raw— Useful but just strips formatting. Doesn't change reasoning.MEGAPROMPT— Overlaps heavily with/autoprompt. One is enough./trim— Helpful for editing, but doesn't shift output quality.XRAY— Sounds cool, performs inconsistently.
How to Stack Codes for Maximum Impact
The real power move is combining codes. Our top 3 stacks:
BEASTMODE+/deepthink— Maximum depth AND qualityOODA+CEOMODE— Strategic framework with executive-level framing/ghost+SENTINEL— Human-sounding text that's been quality-checked
Want All 120 With Before/After Proof?
This post covers the top 15. The Claude Code Cheat Sheet covers all 120 — with before/after examples for every code, combination stacks, and 10 ready-made playbooks.
Three tiers:
- Starter ($5) — All 120 codes with categories and quick descriptions
- Pro ($29) — 40 deep-dive entries with verified test results and stacking guides
- Complete ($49) — Everything plus 10 industry playbooks and quarterly updates
Or browse all codes for free in our interactive prompt library →