StackBlitz WebContainers
StackBlitz's WebContainers technology — browser-native Node.js runtime running fully client-side via WASM. Powers Bolt.new (already in catalog) plus many browser-based AI dev experiences. Founded 2017 by Eric Simons + Albert Pai. $7M Series A 2022. Distinct from server-side sandboxes (e2b / Modal) by running entirely in-browser — zero cloud-execution latency.
Stale · Verified 2026-10-27 · fresh as of 2026-10-27 · 32 cited facts, 1 with a third-party source · 1 recorded change · Suggest a correction
At a glance
- Tier
- T3
- Latest release
- v1.6.4 (2026-04-14) — @webcontainer/api registry fix
- License
- not applicable — not OSS fix
- GitHub
- stackblitz/webcontainer-core — ~4.7k stars, last commit 2025-04 (public issue tracker and docs only; the runtime source is not published) repo fix
- Pricing
- Free for prototypes/POCs; commercial license required for production for-profit use (enterprise pricing via sales) vendor fix
- Funding
- $7M Series A 2022 (GreyLock + GV) vendor fix
- Freshness
- 2026-10-27 fix
- Layer
- agent-infra repo fix
- Licensing
- commercial vendor fix
- SDK languages
- typescript registry fix
- Developer activity
- OpenRank 2.21 (12-mo avg 2.55) · 26 participants — 2026-09 third-party fix
When to use
Optimised for: browser-native AI dev experiences; zero-latency code preview for AI-generated apps
Anti-fit: not applicable — sandbox/runtime, not memory product
Pros & cons
Pros
Browser-native execution (zero cloud-latency); powers Bolt.new (one of biggest AI-coding successes 2024); WebContainers API is unique technology — full Node.js in WASM.
Cons
Browser-only (no native binaries / GPU / persistent disk); commercial WebContainers API pricing has caused some friction; smaller dev mindshare than CodeSandbox.
Claims & capabilities
$7M Series A 2022; founded 2017 by Eric Simons + Albert Pai; WebContainers tech powers Bolt.new + Stackblitz IDE; browser-native Node.js via WASM
Technical surface
- API surface
- WebContainers API (JS)
- Backend storage
- not applicable — sandbox/runtime, not memory product
- Deployment
- Browser-native (client-side); no cloud compute required
- Embedding model
- not applicable — not a memory product
- Multi-tenancy
- not applicable — sandbox/runtime, not memory product
- MCP
- not applicable — sandbox/runtime, not memory product
- A2A
- not applicable — sandbox/runtime, not memory product
- OpenTelemetry
- not applicable — sandbox/runtime, not memory product
Alternatives to StackBlitz WebContainers → live options ranked by shared design, licence, hosting and MCP support
Similar systems
Other ai sandbox & runtime environments in the catalog, ranked by inbound references.
- Daytona T2
Daytona is secure, elastic sandbox infrastructure for running AI-generated code and agent workflows (isolated sandboxes with snapshots, volumes, computer use, MCP server). Pivoted from an open-source cloud development environment; as of June 2026 core development moved to a private codebase and the daytonaio/daytona repo was archived (2026-10-03). SDKs, API clients and CLI/MCP tools are published in the open daytona/clients repo. Founded by the ex-Codeanywhere team (Ivan Burazin).
- e2b T1
e2b provides secure, ephemeral sandboxes (Firecracker microVMs) for AI agent code execution. Each sandbox spins up in <200ms with full Linux environment, Python/Node/etc preinstalled. Substrate for code-agent products including Anthropic Claude Code (artifacts run on e2b), Perplexity, You.com Search, Cognition Devin (partially), and Hugging Face Spaces. Apache 2.0 OSS + managed cloud. $13M Seed + Series A 2024 (Sunflower Capital + a16z).
- Modal Sandboxes T1
Modal Labs ships a serverless container platform with first-class GPU support; Sandboxes feature (2024) adds ephemeral, AI-agent-friendly compute sandboxes. Founded 2021 by Erik Bernhardsson (ex-Spotify ML, author of Luigi + Annoy). $87M total raised through Series B (Lux Capital + Redpoint + Definition + Amplify). Used by major LLM apps for batch inference + agent code execution.
- Anchor (Anchor Browser) T3
Anchor Browser provides cloud-hosted Chromium instances optimised for AI agent use — anti-detect, persistent sessions, residential proxies, CAPTCHA handling. Founded 2023, YC W24. $2.6M seed disclosed. Distinct from Browserless by adding persistent-state + anti-detect optimised for AI-agent web workflows.
- Browserless.io T2
Browserless is a headless-browser-as-a-service — managed Chromium / Playwright / Puppeteer endpoints for web scraping, screenshots, PDF generation, web automation. Increasingly used as substrate for browser-agent products. Founded 2017 by Joel Griffith. Bootstrapped + small seed. Distinct from Playwright OSS — Browserless ships managed Chromium farms with anti-bot circumvention.
- Coder.com T2
Coder.com (formerly Coder Technologies) provides enterprise self-hosted cloud development environments — VS Code Server + dev workspaces on K8s / VMs. $30M Series B 2021 (Redpoint + Founders Fund + Coatue). Founded 2017 by Kyle Carberry + Ammar Bandukwala. 2024 launched 'Coder AI' for agent-execution inside workspaces. Self-hostable AGPL OSS + commercial enterprise.
Sources (31 cited facts, 1 third-party)
Each fact links to the page it came from; the badge says who published it (how to read sources).
- What it is Browser-native Node.js runtime (WASM) — substrate for Bolt.new and AI agents vendor
- What it does & what's distinct StackBlitz's WebContainers technology — browser-native Node.js runtime running fully cli… vendor
- Claims / benefits $7M Series A 2022; founded 2017 by Eric Simons + Albert Pai; WebContainers tech powers B… vendor
- Created 2017 (StackBlitz founded); 2021 (WebContainers tech announced) vendor
- Latest release v1.6.4 (2026-04-14) — @webcontainer/api registry
- GitHub stackblitz/webcontainer-core — ~4.7k stars, last commit 2025-04 (public issue tracker an… repo
- Funding $7M Series A 2022 (GreyLock + GV) vendor
- Customers / scale Bolt.new (StackBlitz's own product); various AI dev experiences; Vercel partner vendor
- Pricing Free for prototypes/POCs; commercial license required for production for-profit use (ent… vendor
- Compliance SOC 2 Type II (path) vendor
- Deployment Browser-native (client-side); no cloud compute required vendor
- HQ San Francisco, US vendor
- Founders / pedigree Eric Simons (CEO; ex-Codeschool, ex-Thinkful); Albert Pai (CTO; ex-Codeschool) vendor
- API surface WebContainers API (JS) vendor
- Runtimes WASM (browser-native Node.js) vendor
- Optimised for browser-native AI dev experiences; zero-latency code preview for AI-generated apps vendor
- Adjacent infrastructure Bolt.new (uses WebContainers); Vercel preview (partnership); competes with CodeSandbox +… vendor
- Pros Browser-native execution (zero cloud-latency); powers Bolt.new (one of biggest AI-coding… vendor
- Cons Browser-only (no native binaries / GPU / persistent disk); commercial WebContainers API … vendor
- Project & sources webcontainers.io/ vendor
- cost-input-usd-per-mtok 0 vendor
- cost-output-usd-per-mtok 0 vendor
- cost-tier free vendor
- cost-pricing-model free-tier vendor
- cost-last-verified 2026-06-29 vendor
- architecture-deployment-locus local vendor
- licensing-bucket commercial vendor
- positioning-platform-vs-product platform vendor
- taxonomy-three-layer-rollup agent-infra repo
- developer-activity-opendigger {"activity":34.67,"as_of":"2026-09","openrank_12mo":2.55,"openrank_current":2.21,"partic… third-party
- sdk-languages typescript registry
What changed
Changes to this record's lifecycle, licence, release, pricing and hosting facts, from the catalog's git history. Subscribe (Atom)
- 2026-10-27
- Latest release “not applicable — sandbox/runtime, not memory product” → “v1.6.4 (2026-04-14) — @webcontainer/api” source
- Pricing “WebContainers API: free for OSS + paid for commercial use (tiered by traffic)” → “Free for prototypes/POCs; commercial license required for production for-profit use (enterprise pricing via sales)” source