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 the recorded response. No data leaves your network, and matched requests reuse your recorded responses. 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 locally in MOCK mode — including HTTPS. Your recorded traffic stays on your own infrastructure; sensitive headers are redacted before anything is written to disk. Recorded matches do not require LLM inference.
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 administrative 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 responses your real upstream actually sent, replayed from your library, inside your own perimeter.
They agreed recording beats guessing
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 — from recordings, 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.
payments-api · upstream OFFLINE
UPSTREAM OFFLINE✓ 29 / 29 GREEN
$ docker stop upstream-api # kill the real API
upstream-api stopped
$ pytest tests/ -v # replayed from Gostly
tests/payments::test_list_customers PASSED
tests/payments::test_get_customer PASSED
· · · · · · · · · · · · · · · · · · · ·
========= 29 passed in 0.85s =========
↳ 0 live calls — served from your library
take the upstream offline — the recorded library still serves, 0 live calls
Feature comparison
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, from recordings
Captures real HTTPS / TLS traffic
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
SAML + OIDC SSO, RBAC, administrative 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
→You want a shareable hosted mock URL in under a minute, with zero install.
→You’re inspecting incoming webhooks or debugging third-party callbacks.
→A frontend needs a fake API and it doesn’t matter where it runs.
→You don’t have — or don’t want — infrastructure to self-host.
Choose Gostly when
→Security or compliance won’t let test traffic leave your perimeter.
→You’d rather record an hour of real traffic than hand-author rules.
→You need deterministic, recorded-response replay in CI — responses from a controlled library.
→You’re recording real HTTPS/TLS traffic, not just typing JSON responses.
→You need SSO (SAML/OIDC), role-based access, and an audit log — in your own perimeter.
Pricing, side by side
Tier
Beeceptor
Gostly
Free
Rate-limited shared hosted endpoint
14-day Pro trial · no credit card required
Pro / Solo
Paid hosted plan (custom domain, higher limits)
$10 / mo single user
Team
Team hosted plan (seats, retention)
$79 / seat / mo
Enterprise
Private Cloud / on-prem on Enterprise — contact sales
Custom pricing
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.
No empty library on day one
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.
gostly.internal / cold-start seeding
cold-start seeding 47 MOCKS · SERVING
⤓
drop a HAR · Postman · OpenAPI file
payments.har — 47 entries · 312 KiB
HARPostmanOpenAPI
✓ GET /customers/:id — seeded
✓ POST /charges — seeded
✓ GET /invoices — seeded
· flip to MOCK — a full library on day one
no empty library — seeded before you record a single call
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.
Mocks that stay in your perimeter
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.