Prompt Engine vs PromptPerfect

Prompt Engine is a web platform for creating, editing, organizing, and optimizing prompts for ChatGPT and other AI systems. Its assisted optimizer reviews prompts and suggests improvements, while prompt testing and dynamic template variables let users preview templates with entered values. Users can assemble multi-step prompt chains, with separate content and variables at each step. A library organizes prompts using folders, subfolders, tags, search, and grid or list views. The curated template collection can be copied to a personal library and customized. The FAQ says prompts can be created for systems including OpenAI, Anthropic Claude, Google, and open-source models. Personal-library prompts are private to the account, while administrators can create public templates; users can export individual prompts or their whole library. The free-forever Hobby plan allows up to 10 prompts and includes basic optimization, 25 credits, limited features, and email support. Pro costs $4.99 a month, with a yearly option at 49 USD per year. A one-time pack of 100 optimization credits costs 4.99 USD. Support resources include documentation, video tutorials, a blog, and email support.

PromptPerfect is an open-source prompt optimizer from Beagle, available as a web app, Chrome extension, and API. In the web app, users submit a draft, choose an optimization mode, and receive rewritten text with an explanation of the changes. Modes include better, specific, cot, developer, research, beginner, product, and marketing. The Chrome extension is described as working on sites including ChatGPT and Gmail. Its API accepts a draft prompt and returns optimized text, an explanation, changes, the original text, provider, and model. Gemini, OpenAI, and Anthropic providers are supported. API keys can be supplied in the request body or as a Bearer token, with the Bearer token taking precedence. The homepage says keys stay in the browser and the project uses the MIT License. The Free plan costs nothing. Hosted Gemini anonymous callers share configured server-key quota.