Now in public beta — join 12,000+ developers

Code together,ship faster.

Real-time CRDT sync. AI review built in. Sandboxed execution.
Everything your team needs, nothing it doesn't.

Live Demo
main.ts — Collab.Code
SC
MR
PP
3 live
main.ts
utils.ts
tests.ts
1// CRDT update — conflict-free by design
2const doc = new Y.Doc()
3const files = doc.getMap('files')
4Marcus
5doc.on('update', (update, origin) => {
6 if (origin === 'remote') return
7 socket.emit('yjs:update', {Sarah
8 roomId, update: Array.from(update)
9 })
10})
✓ All edits converged · 3 participants · 28ms sync

12,000+

Developers

<30ms

Sync latency

99.9%

Uptime SLA

600k+

Sessions

Everything a modern engineering team needs.

Not a toy demo. Every piece is production-grade with a real distributed systems architecture behind it.

CRDT Conflict Resolution

Y.js vector clocks guarantee every edit converges — no merge conflicts, no locking, no data loss. The same engine powering Figma and Notion.

CRDT merge in progress
Aliceinsert('Hello, ')
Bobinsert('World!')
✓ Merged: "Hello, World!" — zero conflict

AI Review, Built In

Streaming code review, auto-fix, test generation, and docs — five review modes, results in seconds.

AI · Live review
WARNO(n²) sort — use Map for O(n)
INFOMissing null check on line 14
OK Error handling looks solid

Live Code Execution

Run JS, TypeScript, Python, Go, and Bash in isolated sandboxes. 8s timeout, 50 KB cap — safe, fast, no setup.

Interview Mode

Built-in countdown timer, problem statement panel, and structured scoring rubric. Everything a technical screen needs.

Redis Pub/Sub Scaling

Socket.IO + Redis fan updates across unlimited server nodes. Horizontal scaling with zero state drift.

Multi-File Workspace

Full file tree, VS Code–style tabs, per-file CRDT sync. Create, rename, and delete files live — all changes propagate instantly to every collaborator.

File Tree

📁 src
📄 main.ts
📄 utils.ts
📁 components
📄 Editor.tsx
📄 Chat.tsx

Open Tabs

main.ts
utils.ts
Editor.tsx
Chat.tsx

Up and coding in 30 seconds.

No config. No install. No friction.

01

Create a room

Name it, pick a language, set visibility. A shareable link is ready in under a second.

02

Invite your team

Share the link. Collaborators join instantly — no install, no account required.

03

Build together

Live cursors, real-time sync, AI review, code execution — all in one place, zero config.

Architecture

Built for scale from day one.

Every architectural decision was made with production in mind — not a hackathon project. What you'd build if you had six months and a distributed systems team.

Consistency
  • Y.js CRDTs
  • Vector clocks
  • Causal ordering
  • UndoManager per user
Transport
  • Socket.IO WS
  • Redis Pub/Sub
  • Polling fallback
  • JWT auth middleware
Execution
  • Sandboxed child_process
  • 8s timeout + SIGKILL
  • 50 KB output cap
  • 5 languages

Loved by engineers who ship.

“

We switched our entire pair-programming workflow to Collab.Code. The CRDT sync is imperceptibly fast — I genuinely can't tell whose keystroke is whose.

SC

A. Faridi

Staff Engineer, Vercel

“

Interview mode is a game-changer. We run all technical screens here now — real editor, real execution, no screen-share lag. Candidates love it.

MR

Team Member

Engineering Lead, Stripe

“

The AI review tab alone saves my team hours per week. It catches what code review misses — edge cases, security issues, complexity you didn't notice.

PP

Team Member

CTO, Arkwright Labs

Interview Mode

Run technical interviews your candidates will remember.

Built-in countdown timer, problem statement panel, and a structured scoring rubric — all in the same real-time editor. No screen-share lag, no separate tool.

  • 45-minute countdown with pause/resume and warning glow
  • Problem panel: paste any LeetCode or custom prompt
  • Structured rubric: correctness, efficiency, communication
  • Interviewer notes (private) alongside the shared editor
  • Auto-saves session summary to your dashboard
Try Interview Mode
Interview · LRU Cache
38:42
1 class LRUCache:
2 def __init__(self, cap):
3 self.cap = cap
4 self.cache = {}
5 self.head = Node()
Correctness
Efficiency
Communication
Code Quality

How we compare

The only platform combining CRDT sync, AI review, sandboxed execution, and interview mode — Pro $30/mo, Enterprise $100/mo.

FeatureCollab.CodeCoderPadHackerRankCodePair
CRDT real-time sync———
AI code review———
Sandboxed execution
Interview mode + timer—
Multi-file workspace———
Version snapshots———
Monthly subscription———
Public share + embed———
Join 12,000+ developers

Ready to build together?

Create a room in seconds. Invite your team. Ship faster than ever before.

See Pricing

Pro $30/mo · Enterprise $100/mo · Cancel any time