Prompt Builder

Assemble clear, well-structured prompts using XML-tagged sections and proven prompting techniques, then copy the prompt or a ready-to-run API request.

Start from a preset

Who and why

Role / personaPut the role in a separate system promptRecommended for API use: the system prompt sets Claude's role for the whole conversation.Context / background

Task required

Input tag name

Input dataWrapped in <document> tags so data never gets confused with instructions.Constraints / rules (one per line)

Examples (few-shot)

Examples show Claude exactly what you want. One to three good examples beat paragraphs of description.

Output

Format

Format details

Tone

Length

Proven techniques

Think step by step before answeringAsks Claude to reason in <thinking> tags, then answer in <answer> tags. Helps with analysis, math and multi-step problems.Ask clarifying questions if ambiguousGood for chat-style tasks where requirements may be incomplete.Say "I don't know" rather than guessingReduces hallucinations by making uncertainty an acceptable answer.Cite quotes from the provided documentsGrounds the answer in your data and makes it easy to verify.

Result

~1 tokens

Add a task to start building your prompt — or load a preset above.

Prompt quality checklist

25%

✗Clear, specific taskState exactly what you want done, using an action verb ("Extract…", "Rewrite…", "Classify…").

✗Context or role providedExplain who the output is for and why. Context helps Claude make good judgment calls.

✗Output format definedSay what the result should look like: structure, sections, JSON shape or length.

✗Includes examplesOne to three input→output examples are often the single biggest quality boost.

✗Has explicit rules or guardrailsAdd constraints such as what to avoid, or allow Claude to say "I don't know".

✓Avoids vague words

✓Input data separated with tags

✗Reasonable lengthThe prompt is very short — add more detail.