Compare
Claude.ai (web app) vs Claude API
Side-by-side comparison of Claude.ai (web app) and Claude API for SKILL.md agent skills — install model, shell access, native support, skill count and best use cases.
Comparison
At a glance
| Dimension | Claude.ai | Claude API |
|---|---|---|
| Vendor | Anthropic | Anthropic |
| Native SKILL.md support | Yes | Yes |
| Verified skills indexed | 32 | 13 |
| Install model | Upload via Settings | POST /v1/skills |
| Shell / Bash access | Sandboxed | Sandboxed |
| Tagline | The Claude web app. Upload skills as zips via Settings → Features. Pro/Max/Team/Enterprise. | Claude API + Skills SDK. Pre-built skill_id values plus custom uploads via /v1/skills. |
Both
9
Skills verified to work on both Claude.ai and Claude API.
Only Claude.ai
23
Indexed for Claude.ai (web app) but not yet verified on Claude API.
Only Claude API
4
Indexed for Claude API but not yet verified on Claude.ai (web app).
Verdict
Which should you pick?
Both support SKILL.md natively, so the choice is about ecosystem fit. Pick Claude.ai (web app) for Anthropic integrations and the workflows it makes easiest; pick Claude API for Anthropic integrations and its specific surface.
Many teams use both — Skills with the SKILL.md spec are portable, and 9 of the skills indexed here are verified on both agents. Browse the per-agent rankings to see which Skills lead on each platform: Skills for Claude.ai (web app) · Skills for Claude API.
FAQ
Common questions
Which is better for SKILL.md skills, Claude.ai (web app) or Claude API?
Both support SKILL.md natively. Claude.ai (web app) has 32 verified skills indexed here; Claude API has 13. 9 skills work on both.
Can I use the same Skill on Claude.ai (web app) and Claude API?
9 of the skills indexed here work on both. The SKILL.md spec is shared, so most skills run cleanly on both — the exceptions are skills that depend on agent-specific tools (Bash, Workflows, MCP patterns).
How do I install a Skill on Claude.ai (web app)?
Settings → Features → Skills. Upload the Skill folder as a ZIP. The Skill becomes available in all your Claude.ai conversations.
How do I install a Skill on Claude API?
POST your Skill zip to /v1/skills. You receive a skill_id. Reference it in your messages request — the model loads the Skill on demand.
Which agent should I pick for most skill workflows?
Both support skills natively. Pick by ecosystem fit: Claude.ai (web app) for Anthropic customers, Claude API for Anthropic customers.
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