
Memrise
Busuu
Babbel
Anki
Lingvist
Rosetta Stone
Mondly
Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.

DuskTools.app
DevToys
JSONLint
CyberChef
regular expressions 101
DevsBox
FreeFormatter
19 free browser-based developer tools — no signup, no tracking, everything runs client-side.
Which is more popular?
Based on our record, Duolingo seems to be more popular. It has been mentioned 70 times since March 2021.
Website, pricing, platforms and company facts side by side.
|
|
|
|
|---|---|---|
| Website | duolingo.com | devtoolkit.site |
| Pricing | — | |
| Company | Startup from the United States · 500 - 999 employees · 2011 | 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Duolingo yet.
DevToolKit is a collection of 19 free online developer tools that run entirely in the browser. No backend, no signup, no data ever leaves your machine. Built with Next.js 14 and Tailwind CSS. Tools include: JSON Formatter & Validator, JSON Tree Viewer with node path copying, YAML-JSON...
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
Walkthroughs and reviews on video.
Duolingo Review: Does it really work?
More videos
No DevToolKit.site 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 Duolingo and DevToolKit.site.
DevToolKit.site's answer:
DevToolKit runs 100% in the browser with zero signup. Unlike CyberChef, which has a steep learning curve with its recipe-based interface, DevToolKit gives you 19 standalone tools — each with a clean, focused UI for a single task. Unlike DevToys, it works on any device with a browser — no desktop app installation needed. And unlike SmallDevTools or similar online toolkits, DevToolKit includes unique tools like a PostgreSQL Config Generator (a free PGTune alternative), a Cron Expression Parser that calculates next 10 actual run times, and a JSON Tree Viewer with click-to-copy node paths. Every tool uses native browser APIs like Web Crypto for hashing — no data is ever sent to a server, which matters if you're working with production JWTs, API keys, or database configs.
DevToolKit.site's answer:
Backend and full-stack developers who deal with JSON, JWTs, SQL, cron jobs, and PostgreSQL configuration on a daily basis. DevOps engineers who need quick encoding, hashing, or regex testing without installing CLI tools. Developers who care about data privacy and don't want to paste production tokens or API responses into random websites that may log input data.
DevToolKit.site's answer:
I'm a backend developer with 10+ years of experience in Python and Go, working on distributed systems and microservices. Every day I was jumping between 5-6 different sites to format JSON, decode a JWT, test a regex, or convert a timestamp — each one bloated with ads, cookie banners, and signup walls. One evening I decided to build all the tools I actually use into a single place where everything runs client-side. The first version had 15 tools and took a weekend to build with Next.js and Tailwind CSS. After getting feedback, I added a PostgreSQL Config Generator (because PGTune hasn't been updated in years), a JSON Tree Viewer, and an HTTP Status Code Reference. It's now at 19 tools and growing based on what developers ask for.
DevToolKit.site's answer:
Next.js 14 with App Router for server-side rendering and per-page SEO metadata. Tailwind CSS for styling with a custom dark theme. Web Crypto API (crypto.subtle) for SHA-1/256/384/512 hashing and cryptographically secure password generation — zero external crypto libraries. FileReader API for client-side Base64 file encoding. All tools are React components with no backend — the entire app is static and deployed on Vercel. Each tool is a separate route with its own metadata, canonical URL, and sitemap entry for independent Google indexing.
DevToolKit.site's answer:
DevToolKit is a free tool with no accounts, so we don't track individual users. It's used by individual developers and small teams who need quick, private access to common dev utilities without enterprise overhead. The tool is designed for anyone who works with APIs, databases, or web development and wants a fast, ad-free, privacy-respecting alternative to existing online tools.
DevToolKit.site's answer:
Three things set DevToolKit apart. First, it includes tools you won't find in other online toolkits — a PostgreSQL Config Generator that replaces PGTune with hardware-aware tuning calculations, a Cron Expression Parser that doesn't just describe the schedule but calculates the next 10 actual execution timestamps, and a JSON Tree Viewer where you click any node to copy its full JavaScript path like data.users[0].email. Second, every tool uses native browser APIs instead of external libraries — hashing runs through Web Crypto API with hardware acceleration, passwords use crypto.getRandomValues(), file encoding uses FileReader — meaning zero dependencies and zero data transmission. Third, each of the 19 tools lives on its own URL with dedicated SEO metadata, so you can bookmark devtoolkit.site/jwt-decoder/ and go straight to it — no navigating through menus or loading tools you don't need.
Share your experience with using Duolingo and DevToolKit.site. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


For AI conversation practice, Duolingo Max is the tier to choose, and we'd call it a useful upgrade only if those extra features matter to you. It sits above the paid Super Duolingo tier rather than directly above the...
Our team of dedicated writers and language enthusiasts is committed to bringing you insightful content and expert advice to enhance your Duolingo experience. From language-learning tips to in-depth analyses of...
Language learning apps such as Duolingo, Babbel and others have millions of registered users worldwide. Duolingo alone has over 300 million registered users.
We have no reviews of DevToolKit.site yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


Duolingo: a language-learning app that uses points, levels, and rewards to keep you motivated. This is the most effective when you do it with your friends or a group of people who share your learning goals. I got really addicted to... Source: over 3 years ago
Hi! I wish I'd seen a post like this a few months ago. I would have been interested then. By now it's a little late for me. I just signed up for the 2 week free trial since that's about all the time I have left before I leave. If you... Source: over 3 years ago
If you want a guided course try Memrise or Duolingo. Source: over 3 years ago
Tracking DevToolKit.site since Feb 2026.
When comparing Duolingo and DevToolKit.site, you can also consider the following products.

Learn a new language with games, humorous chatbots and over 30,000 native speaker videos.
Compare Memrise to Duolingo or DevToolKit.site:

150+ free browser-based developer tools - no sign-up, no tracking, no backend. JSON formatter, Base64 encoder, regex tester, JWT decoder, UUID generator, HTTP status lookup, MIME types, port reference, cron builder & more. Everything runs locally in
Compare DuskTools.app to Duolingo or DevToolKit.site:

Join the global language learning community, take language courses to practice reading, writing, listening and speaking and learn a new language. Learn English with busuu's .
Compare Busuu to Duolingo or DevToolKit.site:

A collection of converters, formaters, encoders, generators and other tools for your Windows desktop.
Compare DevToys to Duolingo or DevToolKit.site:

Babbel is a paid language learning service that aims to strike a balance between thoroughness and cost efficiency.
Compare Babbel to Duolingo or DevToolKit.site:

JSON Lint is a web based validator and reformatter for JSON, a lightweight data-interchange format.
Compare JSONLint to Duolingo or DevToolKit.site: