Binary file upload in Postman - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a binary file upload in API testing?

It is sending a file in its raw binary form (like images, PDFs) to an API endpoint, not as text or encoded data.

beginner

How do you select a binary file to upload in Postman?

In the Body tab, choose 'binary' and then click 'Select File' to pick the file from your computer.

intermediate

Why is it important to set the correct Content-Type header when uploading a binary file?

Because the server needs to know the file type to handle it properly, like 'image/png' for PNG images or 'application/pdf' for PDFs.

intermediate

What is a common mistake when testing binary file uploads?

Trying to send the file as text or JSON instead of raw binary data, which causes the upload to fail or corrupt the file.

beginner

How can you verify a binary file upload was successful in Postman?

Check the API response status code (like 200 or 201) and any response message confirming the upload. You can also download or access the file from the server if possible.

In Postman, which Body option do you select to upload a binary file?

A raw

B binary

C form-data

D x-www-form-urlencoded

The 'binary' option allows you to upload raw files directly.

What header should you usually set when uploading a PNG image file?

A Content-Type: image/png

B Content-Type: application/json

C Content-Type: text/plain

D Content-Type: multipart/form-data

The server needs 'image/png' to recognize the file type correctly.

What happens if you upload a binary file as raw text in Postman?

A The file uploads correctly

B Postman blocks the request

C The server converts it automatically

D The file may get corrupted or rejected

Uploading as text can corrupt the file or cause the server to reject it.

Which HTTP status code usually means a successful file upload?

A 200 or 201

B 404

C 500

D 302

200 means OK and 201 means Created, both indicate success.

Why might you use 'form-data' instead of 'binary' in Postman for file uploads?

A To compress the file automatically

B To upload only text files

C To send multiple files or fields together

D To encrypt the file

'form-data' lets you send files plus other data fields in one request.

Explain the steps to upload a binary file using Postman and how to verify the upload was successful.

Think about how you pick the file, what headers matter, and how you know it worked.

Describe common mistakes when testing binary file uploads and how to avoid them.

Consider what can go wrong with file format and headers.

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