Binary file upload in Postman

Introduction

Uploading binary files lets you send images, documents, or any file type to a server. It helps test if the server accepts and processes files correctly.

Testing image upload features in a web app.

Uploading PDF or document files to a cloud storage service.

Sending audio or video files to a media server.

Checking if file size limits are enforced by the server.

Verifying file type restrictions during upload.

Syntax

Postman

POST /upload HTTP/1.1
Host: example.com
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary

------WebKitFormBoundary
Content-Disposition: form-data; name="file"; filename="example.png"
Content-Type: image/png

<binary data here>
------WebKitFormBoundary--

In Postman, use the 'Body' tab, select 'form-data', add key 'file' (type: File), and choose your file to upload.

The Content-Type header is set automatically by Postman when using form-data with file.

Examples

This example shows how to upload a JPEG image file using Postman's form-data option.

Postman

POST https://api.example.com/upload

Body tab > form-data > key: "file" (type: File) > select file 'photo.jpg'

This example uploads a PDF document file to the server.

Postman

POST https://api.example.com/upload

Body tab > form-data > key: "file" (type: File) > select file 'document.pdf'

Sample Program

This test uploads 'test-image.png' to the server with authorization. It checks if the server accepts the file.

Postman

POST https://api.example.com/upload
Headers:
  Authorization: Bearer your_token_here
Body:
  form-data > key: "file" (type: File) > select file 'test-image.png'

Important Notes

Always check the server response to confirm the upload succeeded.

Use meaningful file names to track tests easily.

Binary upload sends the raw file data without encoding it as text.

Summary

Binary file upload sends raw files to a server for testing upload features.

In Postman, use the 'form-data' option in the Body tab, set key to 'file' (type: File) to select your file.

Check server responses to verify successful uploads.

Practice

1. In Postman, which Body tab option should you select to upload a binary file?

easy

A. GraphQL

B. Form-data

C. Binary

D. Raw

Solution

1. Step 1: Understand Postman Body tab options

   Postman offers multiple Body tab options like form-data, raw, binary, and GraphQL for different request types.

2. Step 2: Identify the correct option for file upload

   For uploading raw files such as images or documents, the 'Binary' option is used to send the file as-is.

3. Final Answer:

   Binary -> Option C

4. Quick Check:

   Binary option = file upload [OK]

Hint: Use 'Binary' in Body tab to upload files directly [OK]

Common Mistakes:

• Choosing 'form-data' which is for key-value pairs
• Using 'raw' which sends text data, not files
• Selecting 'GraphQL' which is unrelated to file upload

2. Which of the following is the correct way to select a file for binary upload in Postman?

easy

A. Enter file path in URL field

B. Click 'Choose Files' after selecting 'form-data' in Body tab

C. Paste file content in 'raw' Body tab

D. Click 'Select File' after choosing 'binary' in Body tab

Solution

1. Step 1: Identify the correct Body tab for binary upload

   Binary upload requires selecting the 'binary' option in the Body tab.

2. Step 2: Understand file selection process

   After choosing 'binary', Postman shows a 'Select File' button to browse and pick the file to upload.

3. Final Answer:

   Click 'Select File' after choosing 'binary' in Body tab -> Option D

4. Quick Check:

   Binary + Select File = correct file upload [OK]

Hint: Always pick 'Select File' after choosing 'binary' [OK]

Common Mistakes:

• Trying to upload file in 'form-data' without key
• Pasting file content in 'raw' which is for text
• Entering file path in URL which is invalid

3. Given this Postman setup: Body tab set to 'binary' with a valid image file selected, what is the expected server response if the upload succeeds?

medium

A. HTTP 200 OK with success message

B. HTTP 404 Not Found

C. HTTP 500 Internal Server Error

D. HTTP 401 Unauthorized

Solution

1. Step 1: Understand typical server responses for file upload

   A successful file upload usually returns HTTP status 200 OK with a confirmation message.

2. Step 2: Analyze other status codes

   404 means resource missing, 500 means server error, 401 means unauthorized access; none indicate success.

3. Final Answer:

   HTTP 200 OK with success message -> Option A

4. Quick Check:

   Success upload = HTTP 200 OK [OK]

Hint: Success = HTTP 200 OK status [OK]

Common Mistakes:

• Confusing 404 as success
• Assuming 500 means success
• Ignoring authentication errors like 401

4. You tried uploading a binary file in Postman but the server responds with HTTP 400 Bad Request. What is the most likely cause?

medium

A. Server is down

B. File was not selected in the binary Body tab

C. Incorrect HTTP method used

D. File size is zero bytes

Solution

1. Step 1: Understand HTTP 400 Bad Request meaning

   This status means the server could not understand the request due to invalid syntax or missing data.

2. Step 2: Identify common binary upload mistakes

   If no file is selected in the binary Body tab, the request lacks the file data, causing a bad request error.

3. Final Answer:

   File was not selected in the binary Body tab -> Option B

4. Quick Check:

   Missing file = HTTP 400 Bad Request [OK]

Hint: Always select a file before sending binary upload [OK]

Common Mistakes:

• Assuming server down causes 400 error
• Using wrong HTTP method without checking
• Uploading empty files without validation

5. You want to automate testing of binary file uploads in Postman using tests. Which script snippet correctly checks if the upload was successful by verifying HTTP status 200?

hard

A. pm.test('Upload success', () => pm.response.to.have.status(200));

B. pm.test('Upload success', () => pm.response.status === '200');

C. pm.test('Upload success', () => pm.response.code == '200');

D. pm.test('Upload success', () => pm.response.statusCode === 'OK');

Solution

1. Step 1: Understand Postman test syntax

   Postman uses pm.test with a callback function and assertion methods like pm.response.to.have.status(200) to check status codes.

2. Step 2: Evaluate each option's correctness

   pm.test('Upload success', () => pm.response.to.have.status(200)); uses correct assertion syntax. pm.test('Upload success', () => pm.response.status === '200'); incorrectly compares number status to string '200'. pm.test('Upload success', () => pm.response.code == '200'); uses wrong property (code is 'OK') and type. pm.test('Upload success', () => pm.response.statusCode === 'OK'); uses invalid statusCode and string.

3. Final Answer:

   pm.test('Upload success', () => pm.response.to.have.status(200)); -> Option A

4. Quick Check:

   Use pm.response.to.have.status(200) for status check [OK]

Hint: Use pm.response.to.have.status(200) in Postman tests [OK]

Common Mistakes:

• Using equality instead of assertion methods
• Comparing status code as string instead of number
• Using wrong property names for response status