
LeetCode
Codility
CodeSignal
iMocha
HackerEarth
Codewars
TestGorilla
HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.

Pinterest
PureRef
Eagle App
Milanote
Allusion
digiKam
weheartit.com
A visual reference manager for creatives. Organize your reference library and build moodboards on an infinite canvas, all in one desktop app.

Which is more popular?
Based on our record, HackerRank seems to be more popular. It has been mentioned 67 times since March 2021.
Website, pricing, platforms and company facts side by side.
|
|
|
|
|---|---|---|
| Website | hackerrank.com | refern.app |
| Pricing | — | |
| Platforms | — | |
| Company | — | Startup from Canada · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of HackerRank yet.
refern is a local-first desktop app for collecting, organizing, and working with visual references. The library side gives you folders, hierarchical tags, smart folders, ratings, color labels, color search by hex, image-to-image visual similarity, and more than 14 typed search operators, all...
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
HackerRank is recommended for students, individual learners, and job seekers looking to improve their coding skills, as well as for companies seeking an efficient way to evaluate candidates' technical abilities during the hiring process.
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing HackerRank and refern..
refern.'s answer:
I'm an artist, and too often I was frustrated: I couldn't find the right pictures, I struggled to organize and keep track of my reference images, and I was juggling too many apps when all I wanted to do was draw. I wanted one tool that could do it all, with every component well integrated. So I made refern.
refern.'s answer:
The flow of collecting references for art usually goes like this:
find references and inspiration online -> save and organize those images -> use them on their own or in a moodboard -> reuse them for the next project or share them with others
Normally that means a different app for each step. refern does all of it in one place, with every part built to work together.
refern.'s answer:
Most tools solve only one part of the reference workflow, so artists end up juggling several. refern combines them in one app: Eagle-style organization and search, a PureRef-style infinite canvas, and an Obsidian-style graph of how your references connect. It never copies your files, so it doesn't double your disk usage. It runs on Windows, macOS, and Linux, works fully offline, and is a $30 one-time purchase with no subscription. Built in Rust, it stays fast even on libraries with hundreds of thousands of images.
refern.'s answer:
Individual artists and creative professionals: illustrators, concept artists, digital painters, designers, and photographers. They collect and organize large libraries of visual references, build moodboards, and study from reference. refern is built for solo creators rather than teams, spanning hobbyists and students through working professionals.
refern.'s answer:
refern is a Tauri v2 desktop app with a Rust backend and a React 19 (with React Compiler) plus TypeScript frontend. Data is stored locally in SQLite (rusqlite) with FTS5 full-text search. The interface uses Tailwind CSS, Zustand, and TanStack Query, with motion/react for animation. The infinite canvas and graph view are built on react-three-fiber and three.js. Thumbnailing, perceptual hashing, and color and visual similarity run in Rust with rayon and SIMD.
Share your experience with using HackerRank and refern.. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


What are LeetCode and LeetCode alternatives good for?LeetCode💡Interested in leveling up your career? Apply to the Formation Fellowship...
HackerRank’s challenges cover a wide range of topics and difficulty levels, allowing developers to enhance their problem-solving skills and learn new algorithms and data structures. The competitive nature of...
HackerRank offers a wide array of challenges across various domains such as algorithms, mathematics, SQL, and functional programming. Its interface is user-friendly, and the platform provides detailed feedback on...
We have no reviews of refern. yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


This way, you transfer what you already know (problem-solving) but only change the syntax. Platforms like Hackerrank are also great to solve the same problem in different languages and learn from other people’s solutions. - Source: dev.to / about 1 year ago
Firstly, solve some common data structure problems with it. Implement some data structures like arrays, linked lists, stacks, queues, etc. You can check common problems on LeetCode, Hackerank or some other resources. - Source: dev.to / over 2 years ago
I don't have a consecutive internet connection and I can't keep up learning process so I started practicing in hackerrank.com I have started some challenges in python and c++ there. Thus I have no internet connection so I cannot practice... Source: almost 3 years ago
Tracking refern. since Mar 2024.
When comparing HackerRank and refern., you can also consider the following products.

Practice and level up your development skills and prepare for technical interviews.
Compare LeetCode to HackerRank or refern.:

Pinterest is a visual discovery tool that you can use to find ideas for all your projects and interests.
Compare Pinterest to HackerRank or refern.:

Codility provides a SaaS platform with advanced validation, security and protection features to evaluate the skills of software engineers.
Compare Codility to HackerRank or refern.:

The simple way to view and organize your multiple reference images.
Compare PureRef to HackerRank or refern.:

CodeSignal is the leading assessment platform for technical hiring.
Compare CodeSignal to HackerRank or refern.:

Unify your creative inspiration in one place. Store anything – inspiring images, design mockups, illustrations, screenshots and more.
Compare Eagle App to HackerRank or refern.: