Claude Skills: What They Are and How to Use Them (2026)

A year ago almost nobody searched for Claude skills; now about 27,000 people in the US do every month (DataForSEO, October 2026). Claude skills turn a long, repeated prompt into something Claude picks up on its own. Write down how you want a job done once (your report format, your brand voice, your spreadsheet checks), save it as a skill, and Claude uses it whenever that job comes up.

What is a Claude skill?

A skill is a folder. Inside is a file called SKILL.md with two required fields at the top, a name and a description, followed by plain-language instructions. The folder can also hold scripts, templates and reference documents (Agent Skills spec).

Claude doesn’t read every skill all the time. It loads them in three steps (Anthropic docs):

Step	What Claude reads	Cost in context
1. At startup	Each skill’s name and description	About 100 tokens per skill
2. When a task matches	The full SKILL.md instructions	Under 5,000 tokens recommended
3. Only if needed	Scripts, references and templates in the folder	Nothing until opened; script code itself never enters the context, only its output

That’s why you can install dozens: only the descriptions sit in memory until one is needed.

Skills launched on 16 October 2025 across the Claude apps, Claude Code and the API (Anthropic). On 18 December 2025 Anthropic published the format as an open standard at agentskills.io, and OpenAI, Cursor, GitHub Copilot and dozens of other tools now read the same files. See Agent Skills explained.

Which plans have Claude skills?

Plan	Skills	Notes
Free, Pro, Max	Yes	Turn on code execution first
Team, Enterprise	Yes	An owner enables code execution and Skills in Organization settings > Plugins & skills

Anthropic’s Help Center lists skills on all five plans (Use skills in Claude); its developer docs list custom skill uploads on Pro, Max, Team and Enterprise. If you can’t see the upload button on a free account, that’s the reason.

How to turn skills on

1. Go to Settings > Capabilities and turn on Code execution and file creation.
2. Open Customize > Skills and switch on the skills you want.
3. Ask for the job as normal. Claude picks the matching skill by itself; you can also name it (“use the PDF skill to…”).

Anthropic’s built-in skills cover Excel, Word, PowerPoint and PDF files, and work as soon as code execution is on. A directory of partner skills (Notion, Canva, Figma, Atlassian and others) lives at claude.com/connectors.

How to upload your own skill

1. Make a folder named after the skill, in lowercase with hyphens, for example weekly-report.
2. Inside it, create SKILL.md:

---
name: weekly-report
description: Writes our weekly client report from raw notes. Use when the user pastes notes and asks for a weekly report or client update.
---

# Weekly report

1. Start with a three-line summary of results.
2. Then a table: task, status, next step, owner.
3. Close with risks and decisions needed. Keep it under 400 words.

3. Zip the folder.
4. In Claude: Customize > Skills > + > + Create skill > Upload a skill, and choose the ZIP.

The common upload errors are a folder name that doesn’t match name, a missing SKILL.md, and odd characters in the name or description (Help Center). Two extra rules in the Claude apps: the name can’t include the words “anthropic” or “claude”, and neither field can contain XML tags. You can also skip the file entirely: describe the skill to Claude and it will build one for you.

Write the description carefully. It’s the only part Claude reads before deciding to use the skill, so say what it does and when to use it, with the words you’d actually type.

Where to find good Claude skills

• anthropics/skills: Anthropic’s official repo (181.8k GitHub stars on 17 October 2026), with document, design, development and enterprise-communication skills, plus a template. Most are Apache 2.0; the Word, Excel, PowerPoint and PDF skills are source-available.
• skills.sh: Vercel’s free directory, ranked by install counts.
• The partner directory at claude.com/connectors for skills from the tools you already use.

There’s more on these, and on paid marketplaces, in the skills hub.

Skills in Claude Code and the API

The same SKILL.md folder works in Claude Code, where you drop it in ~/.claude/skills/ and can also run it as a /command. Developers can attach skills to API calls too: they go in the Messages API container field (up to 20 per request) alongside the code execution tool, and custom skills upload through the /v1/skills endpoint (Skills guide). Custom skills don’t sync between the Claude app, Claude Code and the API, so add them to each one you use.

The downsides

• Code execution has to be on, so skills aren’t available where an admin has turned it off.
• Skills can run code. Anthropic’s advice is to install only skills from sources you trust and to read every bundled file first (docs).
• A vague description means the skill never fires. If Claude ignores your skill, rewrite the description with the exact phrases you use when asking.