Best API Design Tools in 2026
Updated
In short: Apidog is ranked #1 of 26 as of 4 October 2026, ahead of Pact and Postman. The best-ranked option with a free plan is Pact. The lowest first paid tier on this page is Apollo Studio at $5/mo.
When shaping an API, the relevant tool may depend on the specifications you use and the checks or shared workflows you need. Compare OpenAPI and AsyncAPI support, contract validation, mock-server availability and Git synchronization, along with team collaboration and included seats. Free-plan availability and paid-from pricing are listed too. Apidog and Postman are at the top of the ranking, with OpenAPI Studio and SwaggerHub among the next entries; TypeSpec and WireMock also appear early. Use these distinctions to assess how each option aligns with describing, validating and coordinating API work.
26 API design tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
26ranked
16free plans on this page
$5/molowest paid tier
4 Oct 2026last checked
Input list API Design Tools 25 channels on this page · 56 of 200 spec lines stated by the makers
Ch Tool Free planPaid fromOpenAPI supportAsyncAPI supportMock serverContract validationGit synchronizationTeam collaboration Spec sheet Score
01 Apidog Free planYesPaid from9/user/moOpenAPI supportnot statedAsyncAPI supportnot statedMock serverYesContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 3/8spec lines stated 7.9
02 Pact Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock serverYesContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 7.8
03 Postman Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock serverYesContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 7.8
04 oasdiff Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportNoMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 7.7
05 WireMock Free planYesPaid fromnot statedOpenAPI supportYesAsyncAPI supportnot statedMock serverYesContract validationYesGit synchronizationYesTeam collaborationYes 6/8spec lines stated 7.7
06 Microcks Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 7.6
07 Apollo Studio Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationYesGit synchronizationnot statedTeam collaborationYes 3/8spec lines stated 7.5
08 TypeSpec Free plannot statedPaid fromnot statedOpenAPI supportYesAsyncAPI supportNoMock serverYesContract validationYesGit synchronizationnot statedTeam collaborationnot stated 4/8spec lines stated 7.5
09 GraphQL Hive Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock serverYesContract validationnot statedGit synchronizationnot statedTeam collaborationYes 3/8spec lines stated 7.3
10 Mockoon Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 7.3
11 MockServer Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 7.3
12 OpenAPI Studio Free planYesPaid fromnot statedOpenAPI supportYesAsyncAPI supportYesMock servernot statedContract validationYesGit synchronizationYesTeam collaborationYes 6/8spec lines stated 7.3
13 SwaggerHub Free plannot statedPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 0/8spec lines stated 7.3
14 PactFlow Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock serverYesContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 7.2
15 Swagger Editor Free planYesPaid fromnot statedOpenAPI supportYesAsyncAPI supportYesMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 3/8spec lines stated 7.2
16 WSO2 API Designer Free planNoPaid fromnot statedOpenAPI supportYesAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 7.2
17 Schemathesis Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 7.1
18 Redocly Free planNoPaid from10/user/moOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 7.0
19 AsyncAPI Studio Free plannot statedPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportYesMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 6.8
20 Stoplight Elements Free planYesPaid fromnot statedOpenAPI supportYesAsyncAPI supportYesMock serverNoContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 4/8spec lines stated 6.8
21 vacuum Free plannot statedPaid fromnot statedOpenAPI supportYesAsyncAPI supportYesMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 2/8spec lines stated 6.7
22 Smithy Free plannot statedPaid fromnot statedOpenAPI supportYesAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationYes 2/8spec lines stated 6.5
23 MuleSoft Composer Free planNoPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 6.1
24 MuleSoft Omni Gateway Free planNoPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 5.6
25 Assertible Free planYesPaid fromnot statedOpenAPI supportnot statedAsyncAPI supportnot statedMock servernot statedContract validationnot statedGit synchronizationnot statedTeam collaborationnot stated 1/8spec lines stated 5.2
Compare all 25 in a table
| # | Tool | Score | Free plan | From | Free plan | Paid from | OpenAPI support | AsyncAPI support |
|---|---|---|---|---|---|---|---|---|
| 1 | Apidog | 7.9 | Free plan | $9/mo | Yes | 9 /user/mo | — | — |
| 2 | Pact | 7.8 | Free plan | $115.42/mo | Yes | — | — | — |
| 3 | Postman | 7.8 | Free plan | $9/mo | Yes | — | — | — |
| 4 | oasdiff | 7.7 | Free plan | $100/mo | Yes | — | — | No |
| 5 | WireMock | 7.7 | Free plan | Free | Yes | — | Yes | — |
| 6 | Microcks | 7.6 | Free plan | Free | Yes | — | — | — |
| 7 | Apollo Studio | 7.5 | Free plan | $5/mo | Yes | — | — | — |
| 8 | TypeSpec | 7.5 | Free plan | Free | — | — | Yes | No |
| 9 | GraphQL Hive | 7.3 | Free plan | $20/mo | Yes | — | — | — |
| 10 | Mockoon | 7.3 | No | €10/mo | Yes | — | — | — |
| 11 | MockServer | 7.3 | Free plan | Free | Yes | — | — | — |
| 12 | OpenAPI Studio | 7.3 | Free plan | $9/mo | Yes | — | Yes | Yes |
| 13 | SwaggerHub | 7.3 | Free plan | $61.67/mo | — | — | — | — |
| 14 | PactFlow | 7.2 | Free plan | $115.42/mo | Yes | — | — | — |
| 15 | Swagger Editor | 7.2 | Free plan | Free | Yes | — | Yes | Yes |
| 16 | WSO2 API Designer | 7.2 | No | $119/mo | No | — | Yes | — |
| 17 | Schemathesis | 7.1 | Free plan | Free | Yes | — | — | — |
| 18 | Redocly | 7.0 | No | $10/mo | No | 10 /user/mo | — | — |
| 19 | AsyncAPI Studio | 6.8 | No | — | — | — | — | Yes |
| 20 | Stoplight Elements | 6.8 | Free plan | Free | Yes | — | Yes | Yes |
| 21 | vacuum | 6.7 | No | — | — | — | Yes | Yes |
| 22 | Smithy | 6.5 | No | — | — | — | Yes | — |
| 23 | MuleSoft Composer | 6.1 | No | $2,000/mo | No | — | — | — |
| 24 | MuleSoft Omni Gateway | 5.6 | No | — | No | — | — | — |
| 25 | Assertible | 5.2 | No | — | Yes | — | — | — |
Is your tool on this list?
Numbered spots on this list can be sponsored, and a sponsored row is labelled as paid.
Questions about this list
Which API design tool is ranked first on Specifiction?
Apidog is ranked #1 of 26 with a score of 7.9. Pact is second and Postman third.
How many of these have a free plan?
16 of the 25 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Apollo Studio has the lowest first paid tier we found: $5/mo.
How is this list ranked?
Ranked on what each maker publishes, the fullest spec sheet first: how deeply the product is documented, the platforms it runs on, a free tier or trial to test it, and its standing.
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