What Are Claude Skills? A Plain-English Guide With Examples

What are Claude skills, in simple words?

A skill is a folder of instructions, and sometimes extra files, that Claude can load when a task needs it. Anthropic describes skills as folders of instructions, scripts and resources that Claude loads dynamically to do better on specialised tasks.

Think of a skill like a recipe card in a kitchen drawer. The cook does not read every card before making breakfast. They glance at the titles, pull out the one card that fits, and follow it step by step.

Claude works the same way. It knows which skills you have, but it only opens the full instructions when your request matches one.

So when people ask what is a Claude skill, the short answer is this: a reusable how-to guide that Claude follows on its own when the job comes up.

What is inside a Claude skill?

Every skill has one required file called SKILL.md. It is a plain text file you can open in any text editor, like Notepad or TextEdit.

The top of the file has two short fields. The name is the skill's label, written in lowercase letters, numbers and hyphens, up to 64 characters. The description says what the skill does and when Claude should use it, in up to 1,024 characters.

Below that come the instructions: the steps, rules and examples you want Claude to follow. A skill can also hold optional extras in the same folder, such as a template, a longer reference file or a small script that does a fixed job.

Here is a tiny example of what the top of a SKILL.md file can look like:

---
name: brand-voice
description: Writes social posts and emails in our brand voice. Use when the user asks for a post, caption, email or ad copy.
---

# Brand voice
1. Short sentences. Friendly, never pushy.
2. Always end with one clear next step.
3. Never use these words: cheap, guaranteed.

How do Claude skills work?

Anthropic calls the method progressive disclosure. It simply means Claude reads a skill in layers, only as deep as the task needs.

Layer one is the name and description of every skill you have. Claude keeps these in mind all the time. Each one costs about 100 tokens, so you can have many skills without slowing Claude down.

Layer two is the main instructions in SKILL.md. Claude reads them only when your request matches the description. Anthropic suggests keeping this part under about 5,000 tokens.

Layer three is the extra files. Claude opens a reference file or runs a script only if the instructions point to it and the task needs it. Files it never opens cost nothing.

This is why the description matters so much. It is the line Claude matches your request against, so a vague description means Claude may not pick the skill up.

Where can you use Claude skills?

Skills work in three main places, and each one keeps its own copy. A skill you add in one place does not sync to the others.

• The Claude app (claude.ai).: Anthropic's help centre lists skills on the Free, Pro, Max, Team and Enterprise plans. You first turn on code execution and file creation in Settings, then switch skills on or off under Customize. Custom skills you upload are personal to you. On Enterprise, an owner has to enable skills for the organisation.
• Claude Code.: Skills live as folders on your computer, so there is nothing to upload. More on this in the next section.
• The Claude API.: Developers can use Anthropic's ready-made skills or upload their own. Skills here run inside the code execution tool, and uploaded skills are shared across the whole workspace.

What are Claude Code skills?

Claude Code is Anthropic's coding assistant that runs on your computer. Claude Code skills are the same idea as above, stored as normal folders on your machine.

Personal skills go in a folder called ~/.claude/skills/ in your home folder and work in every project. Project skills go in .claude/skills/ inside one project, so everyone who works on that project gets them.

Claude Code can use a skill on its own when your request matches, or you can call it directly by typing a slash and its name, like /brand-voice. Older custom slash commands have been merged into skills and still work.

For exact click-by-click steps on every surface, read how to install Claude skills.

What are Claude skills used for? Everyday examples

The best skills are for jobs you repeat every week and always explain the same way. The three below are illustrations to show the idea, not official Anthropic skills.

• Brand-voice writing.: Your tone, banned words and a few sample posts in one skill. Ask for a caption or email and Claude writes it in your voice without a reminder.
• Notes into a formatted report.: Paste messy meeting notes and Claude turns them into the same report layout every time: summary, decisions, owners and dates.
• Spreadsheet cleanup.: Your rules for fixing a messy export, such as removing duplicates, fixing date formats and naming columns, so every file comes back clean in the same way.

Skills vs prompts vs Projects: what is the difference?

These three are easy to mix up, so here is the short version.

• A prompt: is what you type in one chat. It is great for one-off tasks, but you have to repeat it every time. Our guide on how to prompt Claude shows a simple formula.
• A Project: is a workspace with background files and instructions that are always loaded in the chats inside it. See Claude Projects explained for how they work.
• A skill: is a procedure that loads only when the task needs it, and works across your chats instead of inside one workspace.

Must-have Claude skills to start with

You do not need to build anything to begin. Anthropic ships ready-made document skills for Word, Excel, PowerPoint and PDF files. In the Claude app, Claude uses them automatically when you ask it to create one of those files.

Anthropic also publishes open-source example skills on GitHub. They include brand-guidelines, internal-comms, doc-coauthoring, frontend-design and skill-creator, a skill that helps you write new skills. Reading a few of these is a quick way to see what a good skill looks like.

After that, the most useful skills are usually your own. If you can explain a task to a new teammate, you can turn it into a skill. Our step-by-step guide shows you how to create your own Claude skill without writing code.

Are Claude skills safe to use?

A skill can contain instructions and code, so treat it like installing software. Anthropic's advice is to use skills only from trusted sources: ones you made yourself or ones from Anthropic.

If you find a skill somewhere else, open SKILL.md and any scripts and read them first. Be extra careful with skills that fetch content from outside websites, because that content can carry hidden instructions.

What to read next

Now you know what Claude skills are and how they work. The next step is to put one to use.

Start with how to install Claude skills to add a ready-made skill in a few minutes. Then move on to how to create a Claude skill and build one for a task you do every week.

If you want to see where skills fit into a wider AI workflow for marketing, our AI in digital marketing guide and the AI tools course are good next stops.