
ZIP Code API
ZipCheckup
PostalCodes.info
Smarty
Geocode.xyz
Geoco.io
getAddress.io
Free Zip Code API - Free Postal Code Validation | Zipcodestack

OpenRouter
MandAPI
APIClan.us
Api.Airforce
boldrouter
Requesty.ai
liteLLM
One API key for Claude and GPT models, compatible with the Anthropic and OpenAI formats. Works with Claude Code, Cursor and Codex CLI. Pay as you go, below official list prices.

Which is more popular?
Based on our record, Zipcodestack seems to be more popular. It has been mentioned 3 times since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | zipcodestack.com | apivai.com |
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In their own words, as submitted to SaaSHub.


No description of Zipcodestack yet.
APIVAI is a pay-as-you-go API gateway for Claude and GPT models. One API key works with both the Anthropic Messages format and the OpenAI Chat Completions / Responses formats, so existing tools and SDKs work by changing only the base URL. Key features One key for Claude (Fable, Opus, Sonnet,...
What each product offers, as listed by its team.


Possible disadvantages
No features have been listed yet.
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
No analysis of APIVAI yet.
How often each product is chosen within a category, 0–100% relative to the other.


Share your experience with using Zipcodestack and APIVAI. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.


Using the zipcodestack API in your Node.js application is straightforward. You’ll first need to sign up for a free API key (it only takes a minute). Once you have your API key, you can call the REST endpoints using any HTTP client. Below... - Source: dev.to / about 1 year ago
Zipcodestack - Free Zip Code API and Postal Code Validation. Ten thousand free requests/month. - Source: dev.to / almost 3 years ago
I have seen this request pop up quite a few times. I did a quick search for free APIs of zipcode lookups. This one, named "zipcodestack" (I'm not in any way tied to, endorsing, or promoting them) seemed like a pretty good resource with... Source: over 3 years ago
Tracking APIVAI since Oct 2026.
When comparing Zipcodestack and APIVAI, you can also consider the following products.
REST API for US ZIP, ZIP+4, and Canadian postal codes. Single unified endpoint covers address validation and standardization, radius search (centroid haversine and true spatial polygon intersection), point-to-point distance, autocomplete/typeah
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Check water quality, product recalls, energy rebates, and safety alerts for any U.S. ZIP code. Free reports powered by EPA and government data.
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OpenAI-compatible multi-model API for GPT, Claude, Gemini, DeepSeek and more.
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Postal code lookup API and downloadable country datasets for address validation, checkout, logistics and geocoding workflows.
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OpenAI-compatible AI API gateway for GPT, Claude & Grok. Change baseURL, keep your code. Pay-as-you-go USDT; $0.20 auto credit on signup.
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