Tool · builds in your browser

Prompt Constructor

Answer a few questions and get a prompt assembled in the order that models read best: stable material first, task last, data delimited, format explicit. The prompt is assembled in your browser.

Target model type

Reasoning models get a cleaner prompt with no step-by-step scaffolding; standard models get a "think first" section.

Role and audience

Goal (one sentence: what does done look like?)

Context and inputs (paste documents, data, background)

Constraints (one per line)

Output format

Example of a good output (optional, strongly recommended for standard models)

Tell the model what to do when it is unsure
Ask for a self-check before the final answer
Allow the model to ask clarifying questions first

Your prompt

Open in Claude Open in ChatGPT

Checklist

Role and audience stated
Goal is a single clear sentence
Inputs delimited with tags
Constraints are explicit
Output format is specified
At least one example (standard models)
Task comes last, stable material first

Why this shape

Stable first, task last

Models attend most to the start and end of the context, and APIs can cache an unchanging prefix. Reference material goes at the top, the request at the bottom.

Delimit the data

Tags around pasted content keep instructions inside it from being followed and make long prompts navigable.

Different advice for reasoning models

Standard models benefit from being told to think first. Reasoning models already do, so the constructor leaves out the scaffolding and keeps the problem statement clean.

History

The 2023 version of this tool sent your text to a local Python service that called GPT-3.5. This version assembles the prompt in your browser with fixed rules. Model-assisted rewriting is back as an optional step, now through Claude.