glot.io
Open-source code playground whose runner, docker-run (MIT), executes every request in a fresh, single-use Docker container with network disabled; 44 languages on the hosted site. Useful as a free playground or as a reference MIT container runner; not a supported API to build an agent product on.
Overview
glot.io is an open-source code playground where you run and share snippets in 44 languages. The system is split into repositories under the glotcode organisation: glot-app (the website), glot-languages (language definitions and Docker images) and docker-run, the HTTP API that does the execution. docker-run talks to the Docker daemon over its Unix socket, writes the payload to a fresh container's stdin and reads a JSON result with stdout, stderr and error; every request gets a single-use container that is deleted afterwards, with cleanup handled by background workers and a prewarm pool that still never reuses a container.
Operators set the limits through environment variables: network disabled, memory in bytes, nproc and nofile ulimits, dropped capabilities, a read-only root filesystem, a maximum execution time and a maximum output size. Runs are stateless. The hosted run API was documented in the author's glot-run repositories, which are now deprecated or archived (glot-run2 archived 26 August 2026, with a note that user management will move into glot-www), so the status of a token-based hosted API for third parties is unclear; the site itself publishes no API docs, rate limits or pricing. docker-run is MIT and was updated in August 2026; the glot overview repository carries no licence file.
Notable
- 44 languages listed on glot.io; code runs in a temporary container with network disabled
- docker-run (MIT, about 120 stars) last pushed August 2026; glot-run2 archived 26 August 2026
- The glot overview repository has about 1.7k stars but no licence file
glot.io specifications
| Attribute | Details |
|---|---|
| Isolation | Fresh single-use Docker container per run, deleted afterwards; docker-run configures network off, a memory cap, nproc and nofile ulimits, dropped capabilities and an optional read-only root filesystem; the hosted site says code "runs in a temporary container with network access disabled" |
| Deployment | Hosted platform · Self-hostable |
| Open source | Yes (MIT) |
| SDKs and interfaces | REST API |
| Cold start (vendor claim) | Not documented |
| Max session length | Per run: RUN_MAX_EXECUTION_TIME (seconds) set by the operator; the container is killed when it is reached. No figure is published for the hosted site |
| Persistence | None; containers are never reused, and prewarmed containers serve exactly one request. Snippets (not state) can be saved as public, unlisted or secret on glot.io |
| GPU | No GPU option is documented |
| Networking | Network disabled on the hosted site; DOCKER_CONTAINER_NETWORK_DISABLED is a required setting when self-hosting |
| Pricing | No pricing published; glot.io is free to use and the components are open source |
| Free tier | glot.io is free; free to self-host |
| Compliance | Not documented |
| Regions | Not documented |
Facts from glot.io’s public documentation, verified November 9, 2026. Performance numbers are vendor claims.
Strengths and trade-offs
Strengths
- You want a free, open-source playground to share runnable snippets
- You need a minimal MIT runner (docker-run) that guarantees a fresh container per request
- You are fine with network-less, stateless runs and want to set your own time, memory and process limits
Trade-offs
- No published hosted API documentation, rate limits, SLA or pricing; the token-based run API repos are deprecated or archived
- Stateless and network-less by design
- Isolation is plain Docker; CPU limits are not among the documented settings
- Small maintainer base; the overview repo has not been pushed since August 2024
Good fit for: A free playground and a minimal MIT runner for stateless, network-less snippet execution.
How glot.io compares
| Sandbox | Isolation | Open source | Self-host / BYOC | Cold start (vendor) | Max session | Snapshots / pause | GPU | SDKs |
|---|---|---|---|---|---|---|---|---|
| glot.io | Single-use Docker container | Yes | Yes / No | Not documented | Operator-set per run | No / No | No | REST API |
| Codapi | Locked-down Docker container | Yes | Yes / No | 1-3 s per run (claim) | 5 s default | No / No | No | REST API, JavaScript/TypeScript |
| Piston | isolate in Docker | Yes | Yes / No | Not documented | 3 s run / 10 s compile | No / No | No | REST API |
| Judge0 | isolate (namespaces/cgroups) | Yes | Yes / No | Not documented | 5 s wall (max 20 s) | No / No | No | REST API, Python, JavaScript/TypeScript |
| OneCompiler Code Execution API | Not documented | No | No / No | Not documented | 7-20 s (enterprise) | No / No | No | REST API |
| JDoodle Compiler API | Fresh sandbox per run (unnamed) | No | No / No | Not documented | Not documented | No / No | No | REST API |
Frequently asked questions
What is glot.io?
How does glot.io isolate code?
Is glot.io open source?
How much does glot.io cost?
What are the alternatives to glot.io?
Sources
Cite this page
Agent Sandboxes. (2026). glot.io. agentsandboxes.org. Last reviewed November 9, 2026. https://agentsandboxes.org/sandboxes/glot/
Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.