Postman to Insomnia

What is Postman to Insomnia?

This tool converts an exported Postman Collection (JSON) into an Insomnia export document, so a team using Postman can hand a collection to a teammate on Insomnia without recreating every request by hand.

How it works

The collection's item tree is flattened recursively so requests nested in folders aren't skipped. A single workspace resource is created from the collection's name, and each request becomes an Insomnia request resource with parentId pointing back to that workspace. Postman's {{var}} variable syntax is rewritten to Insomnia's Nunjucks-style {{ _.var }} tags everywhere it appears — in the URL and in header values — via a regex substitution, since the two apps use different templating engines and don't share an environment format. Raw JSON bodies map to Insomnia's { mimeType: "application/json", text: rawBody } shape; urlencoded and form-data bodies map to { mimeType, params: [{ name, value }] }. The final document is wrapped as { _type: "export", __export_format: 4, resources: [...] }, the exact shape Insomnia's own Import Data feature reads.

Features

• Recursively flattens requests nested in Postman folders
• Translates {{var}} to Insomnia's {{ _.var }} tag syntax in URLs and headers
• Maps raw, urlencoded, and form-data bodies to Insomnia's body shapes
• Outputs Insomnia export format 4, ready for direct import
• Copy, download as insomnia_export.json, or load a collection file directly

Example

Input (Postman request): GET {{baseUrl}}/users/:id with header Authorization: Bearer {{token}}.

Output (Insomnia request resource):

{
  "_id": "req_1",
  "_type": "request",
  "parentId": "wrk_1",
  "name": "Get user",
  "method": "GET",
  "url": "{{ _.baseUrl }}/users/:id",
  "headers": [
    { "name": "Authorization", "value": "Bearer {{ _.token }}" }
  ]
}

Common errors

"Not a Postman collection — expected a top-level item array" means the pasted JSON is missing the item array every collection export has — double-check you exported the collection, not just an environment. Note that Postman's :id path variable syntax is left as-is in the URL rather than translated, since Insomnia doesn't use a distinct path-variable notation — it will still resolve correctly as long as your Insomnia request treats it as literal path text.

Best practices

This is a text substitution between two templating syntaxes, not a full environment migration — after importing into Insomnia, create an environment and define values for every _.variableName reference the converted requests use (baseUrl, token, etc.), since Postman environment values themselves aren't carried over.