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Access to worldwide postal code data

The modern platform for creating, sharing, and collaborating on AI prompts. Advanced version control and real-time testing.

Which is more popular?
Based on our record, PostalCodes.app seems to be more popular. It has been mentioned 1 time since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | postalcodes.app | diffyn.com |
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What each product offers, as listed by its team.


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Recommended for
Overall verdict
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing PostalCodes.app and Diffyn.
Diffyn's answer:
Addresses workflow and change management on LLM prompts, provide teams with traceability and visualization of tests across multiple models, provide deeper understading into efficiency of these prompts.
Diffyn's answer:
Diffyn is the platform that specializes on both change management and multi-model analysis.
Diffyn's answer:
React, Next.js, POSTGRESQL
Diffyn's answer:
Professionals incorporating LLMs or AI tools in their workflow and wants to keep track of changes and test their prompts.
Diffyn's answer:
I started working on Diffyn when I notice that prompting has become an essential part of work across many industries. While there are version control platofrms like github, they are not designed for just prompt management are can be overkill such applications, it is also not integrated natively with various LLMs and relevant tools for users to validate ideas and visualise results properly.
Share your experience with using PostalCodes.app and Diffyn. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.


Hey r/API, I made PostalCodes.app, which is an API to access worldwide postal code and zip code range data, I tried to make it simple, and also made simple documentation, would like to hear your thoughts. Source: about 5 years ago
Tracking Diffyn since Jun 2025.
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