axios breaking changes

1.20.0

3 breaking changes, first published August 26, 2026.

• Behavior changed
  Behavioral configuration reads, interceptor replacement, Fetch redirects, HTTP/2 DNS and proxy handling, CIDR NO_PROXY matching and malformed data URI rejection changed; check the referenced PR for compatibility effects. github.com
• Behavior changed
  Requests canceled by navigation now reject with ECONNABORTED rather than resolving with status 0; code relying on the resolved response must handle the error. github.com
• Behavior changed
  Invalid DNS lookup and httpVersion failures now raise AxiosError.ERR_BAD_OPTION_VALUE; code that checks other error codes for these failures must be updated. github.com

1.19.0

50 breaking changes, first published July 29, 2026.

• Behavior changed
  NO_PROXY matching now canonicalizes IPv4 shorthand, octal and hexadecimal forms and honors * entries in bypass lists, so some requests may now bypass or use the proxy differently. github.com
• Behavior changed
  Requests are now blocked after a synchronous request interceptor fails, unless its paired rejection handler resolves successfully. Code that relied on the request still being sent must handle the failure in the rejection handler. github.com
• Behavior changed AxiosHeaders.getSetCookie
  AxiosHeaders#getSetCookie() now consistently returns an array for present values. Code that expected a single string must handle an array. github.com
• Behavior changed formDataToJSON
  formDataToJSON now splits key paths only on dot and bracket notation and keeps other punctuation in keys literally, so output keys may differ from before. github.com
• Signature changed Axios.delete
  Was delete<T = any, R = AxiosResponse<T>, D = any>(url: string, config?: AxiosRequestConfig<D>): Promise<R>; now delete<T = any, R = AxiosResponseDefault, D = any, P = any>(url: string, config?: AxiosRequestConfig<D, P>)... npmjs.com
• Signature changed Axios.get
  Was get<T = any, R = AxiosResponse<T>, D = any>(url: string, config?: AxiosRequestConfig<D>): Promise<R>; now get<T = any, R = AxiosResponseDefault, D = any, P = any>(url: string, config?: AxiosRequestConfig<D, P>)... npmjs.com
• Signature changed Axios.head
  Was head<T = any, R = AxiosResponse<T>, D = any>(url: string, config?: AxiosRequestConfig<D>): Promise<R>; now head<T = any, R = AxiosResponseDefault, D = any, P = any>(url: string, config?: AxiosRequestConfig<D, P>)... npmjs.com
• Signature changed Axios.options
  Was options<T = any, R = AxiosResponse<T>, D = any>(url: string, config?: AxiosRequestConfig<D>): Promise<R>; now options<T = any, R = AxiosResponseDefault, D = any, P = any>(url: string, config?: AxiosRequestConfig<D, P>)... npmjs.com
• Signature changed Axios.patch
  Was patch<T = any, R = AxiosResponse<T>, D = any>(url: string, data?: D, config?: AxiosRequestConfig<D>): Promise<R>; now patch<T = any, R = AxiosResponseDefault, D = any, P = any>(url: string, data?: D, config?: AxiosRequestConfig<D, P>)... npmjs.com
• Signature changed Axios.patchForm
  Was patchForm<T = any, R = AxiosResponse<T>, D = any>(url: string, data?: D, config?: AxiosRequestConfig<D>): Promise<R>; now patchForm<T = any, R = AxiosResponseDefault, D = any, P = any>(url: string, data?: D, config?... npmjs.com

And 40 more in this version.

1.18.1

2 breaking changes, first published June 22, 2026.

• Behavior changed AxiosError.cause
  AxiosError#cause no longer appears in enumerable keys or JSON output, which avoids circular serialisation failures. Code that relied on serialising or enumerating the cause must read it directly instead. github.com
• Signature changed AxiosStatic.Cancel
  Was Cancel: CancelStatic; now Cancel: typeof CanceledError. npmjs.com

1.18.0

2 breaking changes, first published June 14, 2026.

• Behavior changed
  The Node HTTP adapter now removes caller-specified sensitive headers, such as API keys, when a redirect goes to another origin. Code that relies on those headers reaching the redirect target must be changed. github.com
• Behavior changed
  URLs using http: or https: that omit // now fail with ERR_INVALID_URL. Code that passed such URLs must supply well-formed URLs. github.com

1.17.0

8 breaking changes, first published June 3, 2026.

• Behavior changed params
  The params option is now read only from own properties, so values inherited through the prototype no longer affect requests. github.com
• Behavior changed paramsSerializer
  The paramsSerializer option is now read only from own properties, so values inherited through the prototype no longer affect requests. github.com
• Behavior changed resolveConfig
  resolveConfig was changed from an arrow default export to a named function export. Code that relied on the default import must switch to a named import. github.com
• Behavior changed socketPath
  The socketPath option is now read only from own properties, so values inherited through the prototype no longer affect requests. github.com
• Signature changed AxiosHeaders.toJSON
  The TypeScript return type of AxiosHeaders.toJSON() was changed, which can cause type errors in code that depended on the old type. npmjs.com
• Signature changed AxiosRequestHeaders.toJSON
  Was toJSON(asStrings?: boolean): RawAxiosHeaders; now toJSON(asStrings: true): Record<string, string>. npmjs.com
• Signature changed AxiosResponseHeaders.toJSON
  Was toJSON(asStrings?: boolean): RawAxiosHeaders; now toJSON(asStrings: true): Record<string, string>. npmjs.com
• Signature changed isCancel
  The CommonJS isCancel typings now narrow the type to CanceledError<T>, which can cause type errors in code that relied on the broader type. github.com

1.16.1

3 breaking changes, first published May 13, 2026.

• Signature changed AxiosDefaults.parseReviver
  Was parseReviver?: (this: any, key: string, value: any, context?: {source: string}) => any; now parseReviver?: (this: any, key: string, value: any, context?: {source?: string}) => any. npmjs.com
• Signature changed AxiosRequestConfig.parseReviver
  Was parseReviver?: (this: any, key: string, value: any, context?: {source: string}) => any; now parseReviver?: (this: any, key: string, value: any, context?: {source?: string}) => any. npmjs.com
• Signature changed CreateAxiosDefaults.parseReviver
  Was parseReviver?: (this: any, key: string, value: any, context?: {source: string}) => any; now parseReviver?: (this: any, key: string, value: any, context?: {source?: string}) => any. npmjs.com

Check your code

These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.