Beeceptor gives you a hosted mock URL in a minute — on Beeceptor’s cloud, from rules you write by hand. Gostly is a self-hosted platform inside your own perimeter — a Rust proxy in front of your upstream, with its control plane and dashboard alongside (Docker Compose) — that builds its mocks from your real traffic: record an hour, replay it byte-for-byte. No data leaves your network, and every replay is deterministic — the exact bytes the upstream sent, every run. Nothing to start from zero, either — seed the library day one from a HAR, Postman, or OpenAPI file.
Beeceptor earns its popularity honestly. In under a minute you get a hosted endpoint, a clean rules editor, and a request inspector that is genuinely excellent for debugging webhooks and callbacks. For a frontend dev who needs a fake API, or anyone who wants a shareable mock with zero install, it is hard to beat.
The trade-off is the hosting model. Beeceptor mocks live on Beeceptor’s cloud, and the responses are rules you write by hand. That is exactly what most teams want — until two things become true: the traffic cannot leave your network (compliance, customer data, an internal API), or the mock has to match what the real API actually does, not what you remembered to type into a rule.
Gostly is built for that case. You put its Rust proxy in front of your upstream and run the self-hosted stack in your perimeter (Docker Compose); in LEARN mode it records for an hour, then replays the recorded traffic byte-for-byte in MOCK mode — including HTTPS. Your recorded traffic stays on your own infrastructure; sensitive headers are redacted before anything is written to disk. There is no LLM in the request path.
And because it runs as your own single-tenant deployment, the controls a security review asks for are built in: SSO via SAML or OIDC, role-based access control, and an append-only audit log on Team — none of it on someone else’s cloud.
A Beeceptor mock is something you author — a rule you write by hand, or AI-generated data shaped to look real. Gostly’s mock is the recording: the same bytes your real upstream actually sent, replayed byte-for-byte, inside your own perimeter.
In March 2026 Beeceptor shipped contract-drift detection — it records your real traffic to catch where your spec has gone stale. That’s the right instinct, and Gostly is built on it. The difference is what the recording is for: Beeceptor records to patch a hand-maintained OpenAPI document, on its cloud, on the top Scale tier. Gostly records to be the mock — byte-for-byte, in your own perimeter, free on day one. And there is no daily request cap and no per-rule limit to ration: your library is your recorded traffic, so it grows with what you actually send.
take the upstream offline — the recorded library still serves, 0 live calls
| Feature | Beeceptor | Gostly |
|---|---|---|
| Hosting model | SaaS (hosted endpoints) | Self-hosted platform in your perimeter (Docker Compose) |
| Traffic stays inside your perimeter | No | Yes |
| Mock source | Hand-authored rules | Recorded from real traffic |
| Records real upstream traffic | Proxy mode (selective) | Default workflow, byte-for-byte |
| Captures real HTTPS / TLS traffic | No | Yes |
| Deterministic byte-for-byte replay | No | Yes |
| Shareable hosted endpoint, zero install | Yes | No |
| Webhook / request inspector UI | excellent | capture + replay |
| Stateful flows | No | shipping (statechart) |
| Credential headers redacted at capture; data stays self-hosted | n/a (hosted) | Yes |
| AI gap-fill grounded in your real traffic | AI generates synthetic data from a prompt or spec | Opt-in, grounded in your recordings |
| Runs self-hosted in your perimeter (no SaaS) | No | Yes |
| Library on day one (no recordings yet) | Author every rule by hand first | Seed from a HAR / Postman / OpenAPI file — full library before you record |
| Drift detection | Validates traffic against your OpenAPI spec, AI-patches the spec (Scale tier) | Re-records the real upstream and byte-diffs vs ground truth — emits drift events + a freshness score |
| Chaos / failure injection | No | Markov chaos that learns a degradation profile from your traffic |
| Outbound TLS the upstream accepts | n/a (hosted) | JA4-accurate browser-fingerprint impersonation (Pro+) |
| SSO, RBAC, audit log | Hosted account controls (paid) | SAML + OIDC SSO, RBAC, append-only audit log on Team |
Beeceptor offers on-prem / Private Cloud on its Enterprise tier (contact sales); its standard dashboard, sharing, and request inspector run on Beeceptor’s cloud. Gostly is self-hosted free on day one. AI gap-fill on Gostly is opt-in and grounded in your recordings, not a free-text prompt.
Choose Beeceptor when
Choose Gostly when
| Tier | Beeceptor | Gostly |
|---|---|---|
| Free | Rate-limited shared hosted endpoint | OSS proxy (FSL) · unlimited services, self-hosted |
| Pro / Solo | Paid hosted plan (custom domain, higher limits) | $10 / mo single user |
| Team | Team hosted plan (seats, retention) | $79 / seat / mo |
| Self-host / Enterprise | Private Cloud / on-prem on Enterprise — contact sales | $499 / mo Self-host · $25K+ Enterprise |
For a single dev who just needs a hosted endpoint, Beeceptor is cheaper and faster — full stop. The comparison only changes shape when your constraint becomes “the traffic can’t leave our network” or “the mock has to match what the real API actually returned.” At that point self-hosting and recording stop being features and start being the requirement.
The objection that kills most Beeceptor switches is “I have no recordings yet, so I’d be starting from zero.” You aren’t. Drop a HAR capture, a Postman collection, or an OpenAPI spec into the dashboard and Gostly seeds a working mock library before you proxy a single request — the same library your recorded traffic lands in. Then real traffic sharpens it to ground truth. A hand-authored rule is only ever as right as what you remembered to type.
In the dashboard, open Cold-start seeding, drag in the file, pick the service, and commit. The mocks land in the same library your recorded traffic does — flip the proxy to MOCK and they serve immediately. Then run your real test suite through the containerized proxy in LEARN mode to sharpen it to ground truth.
Self-hosted, recorded from real traffic, deterministic in CI. Run it against your staging upstream for an hour and see whether it produces a mock you trust.
Evaluating for a team of 3+? We’d love to talk before you commit.