Master File Uploads with EchoAPI: A Step-by-Step Practical Guide

Stop struggling with API file uploads. This practical guide breaks down EchoAPI's upload feature into simple, actionable steps for effortless testing.

If you’ve ever wrestled with file uploads, you know they can feel like a mini-boss battle in the API world. Luckily, I’ve spent enough time sparring with EchoAPI’s upload feature to gather the most common “what ifs” and turn them into a simple, no-headache guide. Let’s dive in.

Master File Uploads with EchoAPI: A Step-by-Step Practical Guide

File Upload Basics

Here are the essentials you need to know before you start:

1. Should I use multipart/form-data?

Absolutely. This is the HTTP standard for file uploads, and EchoAPI fully supports it. It splits form data and files into parts, each with its own headers — perfect for transmitting binary files.

2. Which parameter key should I use for the file?

It depends on the API. The default is often file, but you might see image, document, avatar, upload, or video. Always check the API docs. If you’re designing the API yourself, you can define the key in EchoAPI.

3. Do I need to send extra metadata?

Sometimes. Adding fields like file_name and media_type makes life easier for the backend. For example, when uploading a profile picture you might also need:

  • user_id: 12345
  • type: avatar

👉 Golden rule: follow the API spec you’re testing against.

Testing File Uploads in EchoAPI

1. Create or Edit an Endpoint

  • Set Content-Type to multipart/form-data
    Don’t add this header manually. EchoAPI (and tools like Postman) automatically generate the right header with a boundary. Adding your own can cause conflicts.
    Just include other headers like Authorization: Bearer <token>.

In Parameters, click Add Parameter, choose File, and enter the field name (e.g. file)

Testing File Uploads in EchoAPI

Set the method to POST (or whatever the API requires)

Testing File Uploads in EchoAPI
Testing File Uploads in EchoAPI
  • Add extra metadata fields (file_name, media_type, etc.) if required.

2. Upload the Test File

Fill in fields as needed

Testing File Uploads in EchoAPI

Select your image, video, or PDF from local storage

Testing File Uploads in EchoAPI

Click Upload Files in the parameter row

Testing File Uploads in EchoAPI

3. Send & Inspect

  • Hit Send

Review the server response in the results panel

Testing File Uploads in EchoAPI

When done, your EchoAPI setup might look like this:

Key Value Type
file my_photo.jpg File
user_id 12345 Text

API Requests to cURL

Want to quickly export your designed API as a cURL command? With just a few clicks in EchoAPI, you can instantly generate the corresponding cURL request.

Click 'Generate Code'

API Requests to cURL


Once the code is generated, you can simply copy and use it.

API Requests to cURL
curl --request POST \
  --url http://httpbin.org/anything \
  --header 'Accept: */*' \
  --header 'Authorization: Bearer <your_token>' \
  --form 'file=@/path/to/my_photo.jpg'

When creating a new HTTP request, just paste the cURL into the URL field. EchoAPI will automatically generate the corresponding API interface.

Quick Breakdown:

  • --request POST: sets the method
  • --header: adds headers (auth, etc.)
  • --form: adds a multipart form-data field
    • file=@/path/to/my_photo.jpg: file is the parameter key, @ points to a local file path

How to Use File Uploads in Postman

  1. Add fields:
    • file (type: File → select local file)
    • file_name (type: Text → filename)

media_type (type: Text → MIME type, e.g. image/jpeg)

How to Use File Uploads in Postman

In the Body, select data.

How to Use File Uploads in Postman

Add auth headers if needed

How to Use File Uploads in Postman

Enter the URL

How to Use File Uploads in Postman

Select POST

How to Use File Uploads in Postman

Troubleshooting File Uploads

If something goes wrong, check these first:

  1. API Spec – Confirm the field names and required metadata.
  2. Don’t touch Content-Type – Let EchoAPI handle it.
  3. Correct Field Types – Use File for files, Text for strings.
  4. Start Simple – Test with just the file, then add metadata later.
  5. Check the Response – Even error messages usually tell you what’s missing ({"error": "Missing field 'file'"}).

EchoAPI’s form-data support makes file uploads painless once you get the setup right. Start small, add complexity step by step, and you’ll be testing file uploads like a pro in no time.