Lifo vs Vercel Sandbox: Cost and Performance
Vercel launched Sandbox as a cloud-based code execution environment for AI agents and developer tools. It's well-engineered — fast startup, per-second billing, up to 8 vCPUs per sandbox, snapshot support. If you're already on Vercel's platform, it's a natural addition.
But if you're searching for a Vercel Sandbox alternative, the reason is almost always cost. Vercel Sandbox charges for Active CPU time, provisioned memory, sandbox creations, network transfer, and snapshot storage. For light usage, it's affordable. For products where every user interaction triggers code execution — AI assistants, interactive tutorials, coding platforms — those costs compound fast.
Lifo takes a fundamentally different approach: code runs in the user's browser. No cloud infrastructure, no per-second billing, no metered dimensions. The cost is $0 regardless of scale because compute happens on the client device.
This post compares the two on what matters most for production products: cost, performance, and architectural trade-offs.
The Cost Breakdown
Let's start with the numbers, because that's where the difference is sharpest.
Vercel Sandbox Pricing
Vercel Sandbox bills across five metered dimensions:
| Metric | What it measures | Rate |
|---|---|---|
| Active CPU | CPU time (excludes I/O wait) | ~$0.128/core-hour |
| Provisioned Memory | RAM × time (GB-hours) | ~$0.021/GB-hour |
| Sandbox Creations | Number of Sandbox.create() calls | $0.60 per million |
| Network | Data in + out (GB) | Metered |
| Snapshot Storage | Saved state (GB/month) | Metered |
Pro plans include a $20/month credit. After that, everything is usage-based.
Here's what Vercel's own docs show for typical scenarios:
| Scenario | Duration | vCPUs | Memory | Estimated Cost |
|---|---|---|---|---|
| Quick test | 2 min | 1 | 2 GB | ~$0.01 |
| AI code validation | 5 min | 2 | 4 GB | ~$0.03 |
| Build and test | 30 min | 4 | 8 GB | ~$0.34 |
| Long-running task | 2 hr | 8 | 16 GB | ~$2.73 |
These assume 100% CPU utilization. Real-world costs are often lower because I/O wait isn't billed. But they're never zero.
Lifo Pricing
| Metric | Rate |
|---|---|
| Everything | $0 |
Lifo is MIT-licensed. Code executes in the user's browser. There's no server, no metered billing, no usage dashboard to monitor.
Cost at Scale: Real Scenarios
Let's model three scenarios for a product that runs AI-generated code for users.
Scenario 1: Small startup — 10,000 sessions/month Each session: 2 min, 1 vCPU, 2 GB RAM
| Vercel Sandbox | Lifo | |
|---|---|---|
| Active CPU | 10,000 × 2 min × $0.128/hr ÷ 60 = $42.67 | $0 |
| Memory | 10,000 × 2 min × 2 GB × $0.021/hr ÷ 60 = $14.00 | $0 |
| Creations | ~$0.01 | $0 |
| Pro credit | −$20.00 | — |
| Monthly total | ~$37 | $0 |
Scenario 2: Growing product — 100,000 sessions/month Each session: 3 min, 2 vCPUs, 4 GB RAM
| Vercel Sandbox | Lifo | |
|---|---|---|
| Active CPU | 100,000 × 3 min × 2 cores × $0.128/hr ÷ 60 = $1,280 | $0 |
| Memory | 100,000 × 3 min × 4 GB × $0.021/hr ÷ 60 = $420 | $0 |
| Creations | ~$0.06 | $0 |
| Pro credit | −$20.00 | — |
| Monthly total | ~$1,680 | $0 |
Scenario 3: Scale product — 1,000,000 sessions/month Each session: 2 min, 1 vCPU, 2 GB RAM
| Vercel Sandbox | Lifo | |
|---|---|---|
| Active CPU | 1M × 2 min × $0.128/hr ÷ 60 = $4,267 | $0 |
| Memory | 1M × 2 min × 2 GB × $0.021/hr ÷ 60 = $1,400 | $0 |
| Creations | ~$0.60 | $0 |
| Pro credit | −$20.00 | — |
| Monthly total | ~$5,648 | $0 |
The pattern is clear: Vercel Sandbox cost scales linearly with usage. Lifo cost stays flat at zero because the compute runs on end-user devices.
Performance Comparison
Cost isn't everything. Here's how they compare on execution performance.
Startup Time
Vercel Sandbox: Sandbox creation takes a network round-trip plus VM provisioning. Vercel's infrastructure is fast, but you're still looking at 100-500ms depending on region and load. Snapshots can reduce warm-start time, but cold starts are inherent to cloud execution.
Lifo: Effectively zero. The runtime is already loaded in the browser. There's no network call, no VM boot, no container startup. For applications that spawn sandboxes on every user interaction (like AI coding assistants), this latency difference compounds across dozens of tool calls per conversation.
Execution Speed
Vercel Sandbox: Server-class hardware. Up to 8 vCPUs, 16 GB RAM per sandbox. For CPU-intensive workloads — compiling code, running test suites, processing large datasets — cloud hardware will outperform a browser runtime. This is Vercel's strength.
Lifo: Browser-class hardware. V8 JIT compilation for JavaScript, WebAssembly at 80-95% of native speed for compute-bound tasks. For typical AI agent workloads — running scripts, file operations, shell commands — browser execution is fast enough. For heavy compute, the server wins.
Latency per Interaction
This is where the architecture difference matters most for AI agents.
An AI agent workflow typically involves multiple tool calls: create a file, run the code, read the output, modify the file, run again. Each interaction with Vercel Sandbox adds network latency — typically 50-200ms per round-trip.
With Lifo, every interaction is local. A 10-step agent loop that takes 1-2 seconds of network overhead with Vercel Sandbox completes with zero network overhead in Lifo. For real-time interactive experiences, this difference is perceptible.
Availability
Vercel Sandbox: Depends on Vercel's infrastructure and your internet connection. Currently limited to the iad1 region. If Vercel has an outage or your user has a bad connection, execution fails.
Lifo: Works offline. No internet dependency. No region restrictions. Code runs as long as the browser tab is open.
Feature Comparison
| Feature | Lifo | Vercel Sandbox |
|---|---|---|
| Execution environment | Browser (Web Workers + Wasm) | Cloud VM (up to 8 vCPUs) |
| Pricing | Free (MIT license) | Usage-based (~$0.128/core-hr + memory + network) |
| Startup time | ~0ms (already in browser) | 100-500ms (network + provisioning) |
| Max resources | Browser memory/CPU limits | 8 vCPUs, 16 GB RAM |
| Offline support | Yes | No |
| Filesystem | Persistent (IndexedDB) | Ephemeral (resets on stop) |
| Snapshots | N/A (files persist natively) | Yes (30-day expiration, paid storage) |
| Region availability | Anywhere (client-side) | iad1 only |
| Concurrency limit | Browser tabs/memory | 10 (Hobby) / 2,000 (Pro) |
| Max session duration | Unlimited | 45 min (Hobby) / 5 hr (Pro) |
| Languages | JS, TS, Python (Wasm), C/Rust (Wasm) | Any language on Linux |
| Network from sandbox | Browser fetch API | Full network stack |
| Open source | Yes (MIT) | No |
| Shell | Bash-like (60+ commands) | Full Linux shell |
| npm packages | 60+ built-in + Wasm packages | Full npm ecosystem |
Where Vercel Sandbox Wins
Server-class compute. If your workloads need 8 vCPUs, 16 GB RAM, or access to server-only tools (native binaries, system libraries, GPU), Vercel Sandbox delivers real hardware. Lifo is constrained to what the browser provides.
Full Linux environment. Vercel Sandbox runs a real Linux OS. Every npm package, every system tool, every language runtime works. No compatibility shims, no Wasm compilation needed.
Snapshots. Save sandbox state and restore it later. Useful for pre-configuring environments (pre-installed dependencies, pre-seeded data) and reducing cold-start time for repeated workloads.
Vercel ecosystem integration. If you're already deploying on Vercel, Sandbox integrates with your existing billing, monitoring, and deployment infrastructure. One vendor, one dashboard.
Concurrency at scale. Pro plans support 2,000 concurrent sandboxes with rate limits of 200 vCPUs per minute. If you need massive parallel execution on server hardware, Vercel Sandbox is built for it.
Where Lifo Wins
Cost — at every scale. From 1 session to 1 million sessions per month, Lifo costs $0. For products where code execution is a core feature (not an occasional add-on), this changes the unit economics of your entire product.
Zero latency per interaction. No network round-trip on any sandbox operation. For AI agent loops with 10-20 tool calls per conversation, this saves 1-4 seconds of cumulative latency per interaction.
Offline and edge. Lifo works without internet. Build products that function on airplanes, in areas with poor connectivity, or in privacy-sensitive environments where code can't leave the device.
No region restrictions. Vercel Sandbox is currently limited to the iad1 region (US East). Lifo runs wherever the user's browser runs — any country, any device, any network.
Persistent filesystem. Files survive browser refreshes and restarts via IndexedDB. Vercel Sandbox filesystems are ephemeral — they reset when the sandbox stops. Snapshots can partially address this, but they're paid storage with a 30-day expiration.
No vendor lock-in. Lifo is MIT-licensed. You own the code, you control the roadmap, and your product never depends on another company's pricing decisions. Vercel Sandbox is proprietary — you're a customer, not an owner.
When to Use Which
Use Lifo when:
- Cost is a constraint and you need code execution at scale
- You're building client-side tools (browser IDEs, interactive docs, AI assistants)
- Your workloads are JavaScript, TypeScript, or Wasm-compilable languages
- Offline support or on-device privacy matters
- You want zero infrastructure overhead — no API keys, no billing, no monitoring
- You're an indie developer or early-stage startup watching every dollar
Use Vercel Sandbox when:
- You need server-class compute (high CPU, lots of RAM)
- Your workloads require full Linux compatibility (arbitrary binaries, system libraries)
- You're already on Vercel and want integrated billing and monitoring
- You need massive parallel execution (hundreds of concurrent sandboxes)
- Session snapshots are important for your workflow
- Your budget comfortably covers usage-based cloud pricing
Use both when:
- Browser-native execution for lightweight, interactive tasks (Lifo) and cloud sandboxes for heavy compute or full Linux workloads (Vercel Sandbox)
- You want a free tier for end users (Lifo) and a premium tier with server resources (Vercel Sandbox)
Getting Started
Try Lifo — zero setup, runs in your browser:
npm install @lifo-sh/core
import { Sandbox } from '@lifo-sh/core';
const sandbox = await Sandbox.create();
// Execute commands — no server, no billing
const result = await sandbox.exec('echo "Zero cost execution"');
console.log(result.stdout);
// Persistent filesystem included
await sandbox.fs.writeFile('/app/data.json', '{"users": 1000}');
Lifo is open-source under the MIT license. Source code on GitHub.
Frequently Asked Questions
Is Lifo a drop-in replacement for Vercel Sandbox?
No — the APIs are different and the execution models are fundamentally different (browser vs cloud). But for common use cases like running scripts, file operations, and AI agent sandboxing, Lifo covers the same ground. Migration involves adapting API calls, not rearchitecting. The biggest question is whether your workloads need server-class hardware or can run in the browser.
How does Vercel Sandbox billing actually work?
Vercel Sandbox bills across five dimensions: Active CPU (time your code uses the CPU, excluding I/O wait), Provisioned Memory (RAM × time in GB-hours), Sandbox Creations, Network transfer, and Snapshot Storage. Pro plans include a $20/month credit. After that, everything is usage-based. See Vercel's pricing docs for current rates.
Can Lifo handle the same workloads as Vercel Sandbox?
For JavaScript, TypeScript, and WebAssembly-compiled languages — yes, for most tasks. Running scripts, manipulating files, executing shell commands, and AI agent tool calls all work well in the browser. Where Lifo can't match Vercel Sandbox is server-class compute: heavy compilation, native binaries, GPU workloads, or scenarios requiring 8 vCPUs and 16 GB RAM.
What about Vercel Sandbox's snapshot feature?
Snapshots let you save sandbox state and restore it later — useful for pre-configured environments. Lifo doesn't need snapshots because its IndexedDB-backed filesystem is persistent by default. Files survive browser refreshes and restarts without any extra API calls or storage costs.
Is Vercel Sandbox only available in one region?
Currently, yes — Vercel Sandbox runs only in the iad1 region (US East). This means users in Europe, Asia, or other regions experience additional latency on every sandbox interaction. Lifo runs locally in the browser, so there are no region restrictions and no geographic latency penalty.