Credit where due: Insomnia (now Kong Insomnia) is one of the best API clients around. Design, debug, and test in one desktop app; Git sync; a genuinely nice touch where you can turn a real response you just received into a mock route in two clicks (send a request → Mock tab → pick a server and route, and the body, headers, and status are captured); dynamic mocking with Liquid templates and faker variables for realistic runtime values; and a self-hostable engine (Insomnia Mockbin — the code that once powered the public mockbin.org, now gone; the repo is source-visible but no longer open source) if you'd rather run the mock engine yourself. If you live in Insomnia as your API client, none of this page argues you should leave it — in fact the last section is about pointing Insomnia at us.
This page is about the moment the built-in mock servers become the bottleneck: when your frontend, your tests, or your teammates need a mock API that behaves like an API, all month long.
Wall 1: mocks are canned examples, not state. Kong's docs describe the model plainly: to create a cloud mock endpoint "you simply need to provide an endpoint and a sample response." A route answers with the example you attached to it. POST something new and the next GET still returns the sample — there is no datastore behind the route, so create-then-read-it-back flows, pagination over growing data, and delete-actually-removes-it flows all have to be faked route by route. (Dynamic mocking's Liquid templating makes the values realistic — a random name on each render — but it's still a template, not data your requests mutate.)
Wall 2: 1,000 mock requests per month on the free plan. That's the Free tier's cap per their pricing page — roughly 33 requests a day, shared across everything that hits your mock URLs. A React dev server with hot reload refetching a list can burn a day's budget in minutes. Past the cap the published add-on is $10 per 25,000 requests; the Pro plan ($12/user/month) raises the included cap to 10,000/month, and only Enterprise ($45/user/month) is unlimited.
Wall 3: an account is required, even to try it. Their FAQ is explicit that mock servers are not available in the local Scratch Pad and that using them means signing up for an Insomnia account. There's no anonymous kick-the-tires path.
Wall 4: every behavior is an authored route. Filtering, sorting, pagination, a 404 for a missing record, an error variant for your retry logic — each one is another route with another hand-authored example (or Liquid template) to maintain as the schema evolves.
Create a hosted project — no account, no desktop app, nothing to author:
curl -X POST https://mockbird.mockbird.workers.dev/api/projects \
-H 'content-type: application/json' -d '{"name":"my-api","preset":"ecommerce"}'
# → {"id":"<PID>","adminKey":"…","baseUrl":"https://mockbird.mockbird.workers.dev/m/<PID>",…}
# 4 resources, realistic seeded records, live immediatelyOr import an OpenAPI spec and get resources plus typed seed data generated from your schemas. Either way, the behaviors you'd author as example routes are just true:
# writes persist (ran against the shared demo before publishing):
curl -X POST https://mockbird.mockbird.workers.dev/m/demo/products \
-H 'content-type: application/json' -d '{"name":"insomnia-guide-check","price":9.99}'
# → {"name":"insomnia-guide-check","price":9.99,"id":31}
curl https://mockbird.mockbird.workers.dev/m/demo/products/31 # → the same record. It's real.
# missing records are real 404s — no route to author:
curl -i 'https://mockbird.mockbird.workers.dev/m/demo/products/999'
# the query toolkit works on every resource, zero configuration:
curl 'https://mockbird.mockbird.workers.dev/m/demo/products?page=2&limit=3&sortBy=price&order=desc'| Insomnia | Mockbird | Notes |
|---|---|---|
| mock server (cloud or self-hosted) | project (POST /api/projects) | hosted URL, no account, live in one curl |
| route + example response | resource records or a custom route | custom routes support status/body/headers/contentType/delayMs + {{query.x}}/{{body.x}} templating |
| Liquid faker variables | faker-style seeded records | realistic data generated at project creation; re-seed with ?seed=N |
| dynamic templating (Liquid) | route templating | honest: theirs is richer; ours covers echo/param/timestamp cases |
| canned CRUD routes | real stateful resources | POST→GET-back persists; PUT/PATCH/DELETE; filters/sort/pagination/search built in |
| error-variant routes | ?mock_status=503, ?mock_seq=502,502,200 | any status on any endpoint, or a deterministic fail-then-recover sequence — no routes authored |
| latency testing | ?mock_delay=2000, ?mock_jitter=800, ?mock_chaos=0.3 | free query params — guide |
| generate mock from a real response | no equivalent | honest: their two-click capture is genuinely nice; closest here is importing a spec, db.json, or Postman collection with saved examples |
| 1,000 free requests/month | 10,000 requests/project/day | ~300x the monthly budget, free |
| self-hosted Mockbin | no self-host | honest: no equivalent — but you can eject anytime via /m/<PID>/db.json + npx json-server |
| Scratch Pad (mockless) | anonymous projects | full mock features with no signup; claim the project later if you want an account |
# pagination + sorting that no one authored:
curl 'https://mockbird.mockbird.workers.dev/m/demo/products?page=2&limit=3&sortBy=price&order=desc'
# error + latency simulation as free query params:
curl -i 'https://mockbird.mockbird.workers.dev/m/demo/products?mock_status=503'
curl 'https://mockbird.mockbird.workers.dev/m/demo/products/1?mock_delay=2000'
# random failures for retry/backoff testing:
curl 'https://mockbird.mockbird.workers.dev/m/demo/products?mock_chaos=0.5'The clean split: Insomnia stays your client; Mockbird becomes the backend that doesn't exist yet. Every Mockbird project publishes a live OpenAPI 3.0 spec at /m/<PID>/openapi.json — import that URL into Insomnia (it imports OpenAPI natively) and you get a ready-made request collection for your whole mock API, including a Postman-format collection at /m/<PID>/postman.json if you prefer that route. Design in Insomnia, hit a mock that's stateful, shared, and not counting down a monthly meter.
# try it with the demo project — import this URL in Insomnia:
https://mockbird.mockbird.workers.dev/m/demo/openapi.json| Insomnia Free | Insomnia Pro/Enterprise | Mockbird | |
|---|---|---|---|
| Price | free | $12 / $45 per user/mo | free while in beta |
| Mock requests included | 1,000/month (then $10/25k) | 10,000/month / unlimited | 10,000/project/day |
| Account required for mocks | yes (not in Scratch Pad) | yes | no |
| Stateful CRUD (POST → GET it back) | no — example responses per route | same model | yes — persistent records, snapshots, restore |
| Pagination/filter/sort/search | authored per route | same model | always on, every resource |
| Dynamic values | Liquid + faker (nice) | same | seeded faker-style data + route templating |
| Capture real response → mock | yes, two clicks | yes | no — import specs/collections instead |
| Self-host option | yes (Mockbin, source-visible license) | yes | no — but full data eject via db.json |
| Full API client attached | excellent | excellent | no — bring your own (or Insomnia!) |
Written by the Mockbird maker — bias disclosed. Where Insomnia genuinely wins: it's a full API client with design, debugging, and testing built in; the capture-a-real-response-into-a-mock flow is excellent; Liquid dynamic mocking is a richer templating language than ours; and the self-hosted Mockbin option means you're never locked to their cloud. Fair note on method: Insomnia's cloud mocks require an account, so unlike most guides on this site we did not exercise their mock servers ourselves — every claim about Insomnia above is taken directly from Kong's official documentation (developer.konghq.com/insomnia/mock-servers) and pricing page (insomnia.rest/pricing) as of August 27, 2026, and the Mockbird demo commands were all run against production before publishing. If their docs or pricing change, we'll update the page.
Full API reference in the docs. More guides: a live API for Hoppscotch · Postman mock server alternative · Mockoon alternative · WireMock Cloud alternative · Beeceptor alternative · Hoverfly alternative · free mock API tools compared. Create your API →