
Delivers structured data science and coding courses with interactive playgrounds, but focuses heavily on data analytics rather than general software engineering.
Coddy records 7,478,457 monthly visits with +17.8% month-over-month growth and Freemium pricing. Zeli records 56,147 monthly visits with -46.8% growth and Free pricing.

Hacker News and AI paper summaries in seven languages
| Dimension / Metric | ![]() | |
|---|---|---|
| Official Domain | coddy.tech | zeli.app |
| Pricing Model | Freemium | Free |
| Monthly Visits | 7.48M (7,478,457) | 56.15K (56,147) |
| MoM Traffic Delta | +1.13M (+17.8%) | -49.3K (-46.8%) |
| Primary Market & Share | 🇺🇸 United States (15.4%) | 🇨🇳 China (65.1%) |
| Direct Visits / mo | 3.13M | 39.95K |
| User Rating | 4.3 | 4.3 |
| Supported Platforms | Website | Website |
Learn to code free with hands-on lessons and instant playgrounds
Short, practice-first coding lessons that run directly in your browser, so you can start learning without installing a compiler or development environment.
Dedicated playgrounds for Python, JavaScript, C, C++, Java, SQL, React, Go, Swift and many other languages let you test snippets and experiment immediately after each lesson.
Structured curricula such as Software Engineer, Frontend, Full Stack, Backend, Data Analyst, Data Scientist, DevOps and game development bundle the skills employers actually ask for.
Streak-style daily coding challenges and progress tracking help learners build a consistent habit and stay motivated between longer courses.

Hacker News and AI paper summaries in seven languages
Each story carries a short summary generated from the linked article plus a standout key quote, so you can judge relevance before clicking through.
The whole feed — titles, summaries and top comment highlights — is available in English, Chinese, Japanese, Korean, German, Spanish and Russian.
Every day gets a permanent page containing every story that hit the front page, retrievable long after the feed has moved on.
Daily AI papers are surfaced with translated titles and AI summaries, making Zeli a research reader as well as a news reader.

Delivers structured data science and coding courses with interactive playgrounds, but focuses heavily on data analytics rather than general software engineering.

SpecialistTeaches computer science and logic through visual interactive puzzles and an AI tutor, but lacks traditional text-editor coding playgrounds.
SpecialistFocuses on hands-on browser-based Linux and DevOps labs with AI guidance, rather than general multi-language programming fundamentals.
SpecialistFocuses on hands-on browser-based Linux and DevOps labs with AI guidance, rather than general multi-language programming fundamentals.

A proactive AI reading lens for papers, videos, and web pages
A proactive AI reading lens for papers, videos, and web pages
Free AI Summarizer for text, articles, URLs and images
Free AI Summarizer for text, articles, URLs and images

SpecialistKhan Academy's AI tutor and teaching assistant for guided, Socratic learning
SpecialistKhan Academy's AI tutor and teaching assistant for guided, Socratic learning
SpecialistYour personal AI tutor — generate a course on anything in seconds
SpecialistYour personal AI tutor — generate a course on anything in seconds
AI-powered platform to read, write, and stay current with research

Turn any long article or webpage into a clean, clickable summary in one click
Turn any long article or webpage into a clean, clickable summary in one click
AI summaries and study guides for scientific papers
AI summaries and study guides for scientific papers
AI research workspace for searching, reading and connecting papers
AI research workspace for searching, reading and connecting papers
Highlight dense research text and get plain-language explanations instantly
Highlight dense research text and get plain-language explanations instantly