Smarty
Zipcodestack
PostalDataPI
Geoco.io
Melissa Data Quality
Loqate
usZIPCodes.org
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

Treehouse
edX
Docebo
Pluralsight
Khan Academy
Talent LMS
Codecademy
The ClassMarker online testing website, is a professional, easy to use, online quiz maker that marks your tests and quizzes for you. Create online quizzes free quiz maker. Web-based online testingWeb-based online testing service | Free quiz maker.

Which is more popular?
Website, pricing, platforms and company facts side by side.
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ZIP
ZIP Code API
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|---|---|---|
| Website | zip-codes.com | classmarker.com |
| Pricing | — | |
| Company | Startup from the United States · 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.

API for US ZIP, ZIP+4, and Canadian postal code data. One unified endpoint set covers North America — no separate APIs by country or data type. What it does Address validation and standardization — production-grade parser with ZIP+4 append, refreshed monthly Radius search — centroid haversine and...
No description of ClassMarker yet.
What each product offers, as listed by its team.

Possible disadvantages
An editorial look at what each product does well and who it suits.

Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
ClassMarker is recommended for educators, trainers, and businesses seeking an efficient way to manage online assessments. It's particularly useful for teachers conducting exams, HR professionals managing employee evaluations, and trainers delivering certification tests.
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How to Use ClassMarker - A Free Online Test Maker
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ClassMarker is yet another online test maker tool that offers secure, professional web-based online testing solutions for business, training & educational assessment. It is easy to use and offers several customization...
ClassMarker is another all-in-one quizzing solution on our list. It’s a cloud-based test builder that can be used by instructors and online storage for published assessments that students can log in to and take...
When comparing ZIP Code API and ClassMarker, you can also consider the following products.

Smarty provides address validation, autocomplete, geocoding and reverse geocoding services covering addresses in over 240+ countries.
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Treehouse is an award-winning online platform that teaches people how to code.
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Free Zip Code API - Free Postal Code Validation | Zipcodestack
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Best Courses. Top Institutions. Learn anytime, anywhere.
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The most affordable postal code API. 240+ countries, sub-5 ms responses. Simple, elegant, transparent.
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Docebo Learning Management System is the best cloud LMS system on the market for online training. AICC SCORM xAPI compliant. Mobile elearning platform
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