Default reponseType is not json

Describe the bug

In the document, responseType default value is json

  // `responseType` indicates the type of data that the server will respond with
  // options are: 'arraybuffer', 'document', 'json', 'text', 'stream'
  //   browser only: 'blob'
  responseType: 'json', // default

But it is undefined when running axios.
If we do not set it manually, it will prevent throwing a JSON parse error, even if silentJSONParsing is set to false when parsing an unexpected JSON string.

axios/lib/defaults/index.js

Lines 103 to 120 in 8092aee

    
           const JSONRequested = this.responseType === 'json'; 
        
           if (utils.isResponse(data) || utils.isReadableStream(data)) { 
        
             return data; 
        
           } 
        
           if (data && utils.isString(data) && ((forcedJSONParsing && !this.responseType) || JSONRequested)) { 
        
             const silentJSONParsing = transitional && transitional.silentJSONParsing; 
        
             const strictJSONParsing = !silentJSONParsing && JSONRequested; 
        
             try { 
        
               return JSON.parse(data, this.parseReviver); 
        
             } catch (e) { 
        
               if (strictJSONParsing) { 
        
                 if (e.name === 'SyntaxError') { 
        
                   throw AxiosError.from(e, AxiosError.ERR_BAD_RESPONSE, this, null, this.response); 
        
                 } 
        
                 throw e;

It has a similar issue, but does not change it.

since we have gone back and forth a lot on this we will probably not make any new changes till we cut a v1.
Maybe we should fix it in v1.
#3116

I suggest adding a default value in the

axios/lib/defaults/index.js

Lines 36 to 40 in 8092aee

    
           const defaults = { 
        
             transitional: transitionalDefaults, 
        
             adapter: ['xhr', 'http', 'fetch'],

To Reproduce

Set the backend controller to return invalid JSON
Or
Use Fiddler to intercept the response and modify the JSON to invalid JSON.

Code snippet

const response = await axios.get(uri, {
	transitional: { silentJSONParsing: false },
});

Expected behavior

Just set silentJSONParsing as false, when receiving invalid JSON, then throw a JSON parse SyntaxError.

Axios Version

1.13.2

Adapter Version

No response

Browser

No response

Browser Version

No response

Node.js Version

No response

OS

No response

Additional Library Versions

Additional context/Screenshots

@leozhu7

@leozhu7 Please assign me this issue

fix: silentJSONParsing=false should throw on invalid JSON (axios#7253)

@jasonsaayman

Hi! @jasonsaayman
I’ve opened a PR fixing the issue where silentJSONParsing: false did not throw on malformed JSON unless responseType: 'json' was explicitly set.
The fix corrects the logic in lib/defaults/index.js and includes a regression test to ensure expected behavior.

Let me know if anything needs adjustment!

fix: set default responseType to 'json' to match documentation

fix: silentJSONParsing=false should throw on invalid JSON (#7253) (#7257

Revert "fix: silentJSONParsing=false should throw on invalid JSON (#7253

merge v1 to main (#7345)

fix: silentJSONParsing=false should throw on invalid JSON (axios#7253) (

Revert "fix: silentJSONParsing=false should throw on invalid JSON (ax…

fix: make silentJSONParsing: false work without explicit responseType

docs: clarify silentJSONParsing requires explicit responseType: 'json'

fix: make silentJSONParsing: false work without explicit responseType

chore(deps): update dependency axios to v1.13.4 (#18)

docs: clarify silentJSONParsing requires explicit responseType: 'json' (

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Default reponseType is not `json` #7253

Describe the bug

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Code snippet

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	const JSONRequested = this.responseType === 'json';

	if (utils.isResponse(data) \|\| utils.isReadableStream(data)) {
	return data;
	}

	if (data && utils.isString(data) && ((forcedJSONParsing && !this.responseType) \|\| JSONRequested)) {
	const silentJSONParsing = transitional && transitional.silentJSONParsing;
	const strictJSONParsing = !silentJSONParsing && JSONRequested;

	try {
	return JSON.parse(data, this.parseReviver);
	} catch (e) {
	if (strictJSONParsing) {
	if (e.name === 'SyntaxError') {
	throw AxiosError.from(e, AxiosError.ERR_BAD_RESPONSE, this, null, this.response);
	}
	throw e;

	const defaults = {

	transitional: transitionalDefaults,

	adapter: ['xhr', 'http', 'fetch'],

Default reponseType is not json #7253

Description

Describe the bug

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Code snippet

Expected behavior

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Adapter Version

Browser

Browser Version

Node.js Version

OS

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id-87 commented on Nov 24, 2025

Rudrxxx commented on Nov 24, 2025

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Default reponseType is not `json` #7253