Phi Lab

Phi Lab

Programming Hero Instructor Lab

Programming Hero Instructor Lab

Don't just read code.
Watch it think. Say it out loud.

Phi Lab is a hands-on platform that takes you from your first console.log to job-ready — a guided path of interactive labs where you watch JavaScript actually run, rebuild real UIs, and practice interviews out loud with AI.

Start the Path Step through code

Free · No signup · Runs in your browser

8 interactive labs One guided path AI voice feedback
Φ
heapcall-stack▶ run
The PathStart here

One guided path. Every lab, in the right order.

Eight labs is a lot of doors. The Path is your AI-personalized journey from your first console.logto job-ready — it decides what you do next, pulls in the right lab for each skill, and only lets you advance once you can prove you've got it.

  • Personalized to your goal

    A short onboarding sets your goal and pace, then the AI plots your route and an honest ETA to job-ready.

  • A daily quest, not a playlist

    Each day the Path budgets a session you can actually finish, and a weekly report tells you what to fix next.

  • Mastery gates, not checkboxes

    You don't clear a node by clicking through it — you clear it by doing the thing and explaining it back.

Start the Path

Module 2 · Execution model

✓

Variables & scope

2

The call stack

see itbuild itexplain itsay it
🔒

Closures

On track~6 weeks to job-ready
The Labs

Nine labs. One goal: make it click.

Every concept here is something you run, watch, or say — not just something you read.

Js Motion Lab

A step-by-step JavaScript visualizer. Press run and watch every variable, stack frame, and heap object move.

Memory & call stackHeap graphTimeline & breakpointsQuiz modeShareable links
1 function push(stack, v) {
2 stack.push(v)
3 return stack
4 }
push()
main()
Open Js Motion Lab

Pixel Lab

Rebuild a UI from a picture in HTML and CSS. Your code renders in a real browser on our side and gets diffed against the target, pixel by pixel.

27 challenges · navbars → whole pagesScored in a real browserDiff & slide compareUnlock the run

target

phiLabsHive

yours

phiLabsHive
100%
Open Pixel Lab

Code Lab

Solve JavaScript and TypeScript problems in a real editor. Your code is graded on the server against hidden cases — then enter timed contests and climb the leaderboard.

JS & TS problemsServer-graded in QuickJSTimed contests + leaderboardXP & badges
1 function twoSum(nums, t) {
2 const seen = new Map()
3 // …
4 }
Accepted · 12/12
Open Code Lab

Interview Lab

A live AI voice interview. Pick a topic and difficulty, speak for two minutes, get a scored report with per-question feedback.

10 topics · HTML → MongoDBLive transcriptGemini-poweredScore ring + sub-scores
Explain the event loop.
It's a single-threaded queue that...
Open Interview Lab

Support Session

A live voice call with a supportive AI — about a bug, something on your mind, or where to go next. Share your screen so it can see the error, and rate the help afterwards.

Live voice helpCoding · mental · guidanceShare your screen10-minute sessions
I'm stuck and a bit burnt out…
Let's slow down. Want to share your screen?
Open Support Session

Feynman Lab

Learn by teaching. Explain a concept out loud to a curious AI beginner that asks the naive questions — then get a clarity score on your explanation.

Teach it out loudAI asks the naive questionsClarity scoreMirror test
A closure remembers its outer variables…
Wait — remembers them how? Can you show me?
Open Feynman Lab

English Lab

Spoken technical English for developers. Roleplay a standup, code review or salary talk with an AI partner, then get a fluency score and say-it-better fixes.

5 work scenariosVoice roleplaySay-it-better fixesFluency score
I am agree with this approach.
I agree with this approach.
Open English Lab

Quiz Lab

Test your knowledge with AI-generated quizzes. Pick topics from HTML to MongoDB, choose your difficulty, and earn XP for every correct answer.

9 topics · HTML → MongoDBGemini-powered3 difficulty levelsXP rewards

Which keyword creates a block-scoped variable?

A. var
B. let
C. const
D. function
✓ Correct— 5 XP earned
Open Quiz Lab

Project Reviewer Lab

Submit a GitHub repo and live link, then get an AI-style review across structure, naming, responsiveness, SEO, accessibility, and performance.

Github + live linkStructure + namingSEO + accessibilityPerformance feedback
github
github.com/phi-lab/project-reviewer-demo
live link
project-reviewer-demo.vercel.app

overall

7.8/10
Folder structure
Accessibility
Too many prop drillings.
Missing loading states.
No error handling.
Open Project Reviewer Lab
NewThe Hive

Hive — the helpdesk that answers itself

A social feed for the questions that stall you. The Hive AI replies instantly, tries a different angle when you're still stuck, and hands you to a mentor when it runs out of ideas.

  • The AI answers first

    Post a problem and get a worked answer in seconds — with the corrected code, not just a hint.

  • A human when it matters

    Three failed attempts, or anything sensitive, and a mentor takes over — holding everything the AI already tried.

  • Answers become the Honeycomb

    Solved threads are distilled into a searchable knowledge base. Everything else expires in seven days.

Enter the Hive
First answer in seconds, not hours
How it works

From first console.log to job-ready

A guided path for beginner-to-advanced learners — one loop of see, test, speak, and measure.

1

Learn by seeing

Run real JavaScript in Js Motion Lab and watch memory move instead of guessing what happens.

2

Test your intuition

Quiz mode pauses mid-execution and asks "what happens next?" — before you see the answer.

3

Practice speaking

Interview Lab drills you out loud on the topics companies actually ask about.

4

Measure & improve

Scored reports break down communication, depth, and accuracy — so you know exactly what to fix.

Why Phi Lab

Built like a lab, not a lecture.

Our goal is simple: turn passive reading into active practice, and carry you from complete beginner to job-ready. Everything is voice-first where it matters, runs in the browser, and scales from easy to expert.

Zero setup

Everything runs in your browser — no installs, no accounts.

Beginner → advanced

Easy, medium, and expert difficulty in every lab.

Real internals

See the call stack, heap, and event loop — not a diagram of them.

Voice-first practice

Speak your answers out loud, the way a real interview works.

Shareable everything

Send a link to any visualizer run and pick up right where it left off.

Dark mode & keyboard friendly

Built for long study sessions, not just a demo.

Second Brain

Save articles, videos, and notes — then chat with your knowledge using AI.

Your first step starts in the browser you already have.

No signup, no setup — start the guided Path, or jump straight into a lab.

Start the Path Take a mock interview