
Codecademy
Exercism
LeetCode
Treehouse
edX
Coursera
Udemy
Achieve code mastery through challenge.

AgentGatePay
x402
Real-world tasks your agent can't do alone.

Which is more popular?
Based on our record, Codewars seems to be a lot more popular than Underscore Done. While we know about 160 links to Codewars, we've tracked only 1 mention of Underscore Done.
Website, pricing, platforms and company facts side by side.
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| Website | codewars.com | underscoredone.com |
| Pricing | ||
| Company | — | Startup from the United States · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Codewars yet.
Underscore Done (_done) is a suite of pay-per-call utility APIs built for AI agents. No API keys, no subscriptions - agents pay per request with USDC via the x402 protocol
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
Codewars is recommended for beginner to advanced programmers who enjoy learning through practice and are interested in improving their algorithmic thinking and coding skills in a gamified environment. It is particularly beneficial for those preparing for coding interviews or seeking to reinforce their programming knowledge in a fun and interactive way.
No analysis of Underscore Done yet.
Walkthroughs and reviews on video.
Codewars Review & Tips
More videos
No Underscore Done videos yet. You could help us improve this page by suggesting one.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Codewars and Underscore Done.
Underscore Done's answer:
We provide data and actions that AI cannot achieve.
Also we don't require accounts, registration, api keys. And we charge per usage and never charge monthly subscriptions.
Underscore Done's answer:
Ai Agents that work on behalf of people.
Share your experience with using Codewars and Underscore Done. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


Edabit offers a learning experience similar to learning a new language, focusing on smaller and more frequent exercises that build proficiency over time. Like Codewars, Edabit provides many challenges that increase in...
In conclusion, while Leetcode remains a valuable resource for coders, the platforms listed above offer varied approaches to learning and improving coding skills. Whether you're drawn to the gamified learning...
This LeetCode alternative has excellent features for anyone looking to sharpen their coding skills. Codewars uses kata, which are small coding exercises that are community developed to help you master your language of...
We have no reviews of Underscore Done yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


Recently, I was working on a coding kata on codewars.com. Early on, I started thinking that a potential solution might utilize recursion, a concept that involves a function calling itself. However, I quickly realized that my grasp of... - Source: dev.to / almost 3 years ago
Get more involved. Look into internships and junior SWE positions to get a sample of what you'd be applying for once you graduate. Solve coding challenges, start working on a portfolio of your personal works. I recommend codewars.com for... Source: almost 3 years ago
I'd recommend to play around with some basic coding challenges on leetcode.com or codewars.com. If the course prepared you well you won't find this useful, but playing around with them will make sure that you are comfortable with basics... Source: about 3 years ago
_done is a catalog of small, pay-per-call utility APIs aimed at AI agents: things like DNS and WHOIS lookups, screenshots, OCR, hashing, QR codes, and SEO extraction. Every call costs one cent in USDC over x402. There's no account and no... - Source: dev.to / 16 days ago
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An open protocol for internet-native payments from Coinbase
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Practice and level up your development skills and prepare for technical interviews.
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Treehouse is an award-winning online platform that teaches people how to code.
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