[Bug]: Android Capacitor Returns UTF-8 Binary String Instead of Blob for Binary Responses

[layola13]

Capacitor Version

Capacitor Doctor

Latest Dependencies:

@capacitor/cli: 7.1.0
@capacitor/core: 7.1.0
@capacitor/android:
7.1.0
@capacitor/ios: 7.1.0

Installed Dependencies:

@capacitor/ios: not installed
@capacitor/cli: 7.1.0
@capacitor/core: 7.1.0
@capacitor/android: 7.1.0

[success] Android looking great! 👌

Other API Details

npm -v 10.9.2

 node -v v23.9.0

Platforms Affected

• iOS
• Android
• Web

Current Behavior

When making network requests with responseType: 'blob' on Android with Capacitor, instead of receiving a proper Blob object like on web platforms, the response is a UTF-8 encoded binary string. This inconsistency causes issues when trying to handle binary data like audio files across different platforms.

• On web: response.data is a proper Blob object

• On Android: response.data is a UTF-8 encoded binary string

Expected Behavior

When making a request with responseType: 'blob', the response should be a standard Blob object on all platforms (web and Android), allowing consistent code handling.

Project Reproduction

https://gist.github.com/layola13/55bd89421c9e82d066d584b80f0da551

Additional Information

This inconsistency makes it difficult to handle binary responses in a cross-platform manner. Ideally, Capacitor should normalize the response type to be consistent with web behavior, returning a proper Blob object when responseType: 'blob' is specified.

[ionitron-bot]

This issue needs more information before it can be addressed. In particular, the reporter needs to provide a minimal sample app that demonstrates the issue. If no sample app is provided within 15 days, the issue will be closed.
Please see the Contributing Guide for how to create a Sample App.
Thanks! Ionitron 💙

[layola13]

https://github.com/layola13/capacitor-blob-bug-reproduction
@jcesarmobile

web

test1 ❌
test2 ✅
test3 ✅
test4 ❌
test5 ✅ //from https server

andoird

test1 ❌
test2 ✅
test3 ✅
test4 ❌
test5 ❌//from https server

[ionitron-bot]

This issue has been labeled as type: bug. This label is added to issues that that have been reproduced and are being tracked in our internal issue tracker.