axios: Getting 'Cross-Origin Request Blocked' on a GET request
Summary
I’m making a GET request to 4chan’s API for retrieving threads from a board. This is my code:
const board = this.props.routeParams.tag;
var config = {
headers: {'Access-Control-Allow-Origin': '*'}
};
axios.get('https://a.4cdn.org/' + board + '/threads.json', config)
.then(function (response) {
console.log(response.data);
});
I receive the following warning:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://a.4cdn.org/a/threads.json. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
As seen above, I have added the relevant header, but it does not solve the issue. I made the same request from my terminal using cURL and it worked fine.
Context
- axios version: e.g.: v0.16.0
- Environment: e.g.: node v6.9.4, Firefox 51.0.1, Ubuntu 14.04
About this issue
- Original URL
- State: closed
- Created 7 years ago
- Reactions: 111
- Comments: 143
Commits related to this issue
- Getting 'Cross-Origin Request Blocked' on a GET request 12:07 — committed to ev15963/frontend_202012 by ev15963 3 years ago
Access-Control-Allow-Origin is a response header, not request header: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin
axios.get(url, { headers: {‘Access-Control-Allow-Origin’: *} } ) means nothing!
try axios.get(url, { crossdomain: true })
Any news on this? I’m pretty much in the same boat…
Read this, everyone. https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS
As a temporary solution you can use this : https://chrome.google.com/webstore/detail/cors-toggle/omcncfnpmcabckcddookmnajignpffnh
I did not find anything better for now …
if you want to fetch data from a third party api or url that has a issue with its CORS header(missing or contains multiple values) I think the only solution for this is use this link “https://cors-anywhere.herokuapp.com/” I use the link for small projects but for big projects you may want to create your own api to handle the calls and creating the api you can use the open source project https://github.com/Rob--W/cors-anywhere/ .
This one will work:
i always find reference to that MDN document not very helpful. its a long document and it doesnt directly address the question at hand. what do i do if i dont have access to the server side codebase and want to access this API?
The server needs to respond with CORS headers on the options call. If you are using nodejs/express, you can fix this for all endpoints with:
But that’s a little loose. Probably want to tighten up for production.
it’s 2018 now, is there any update?
The error is still prevalent.
My advice: use a different library.
it’s 2021 now, is there any update? 😃
Thank you for the suggestion. I have updated my code to route the request through a proxy:
However, I’m still getting this error:
I have searched through various forums and questions on Stack Overflow and I can’t seem to find any solution to this. It would be appreciated if someone could provide some insight.
it’s 2020 now, is there any update? 😃
@ronnin For the record, I tried out your solution, but it doesn’t work.
we have self-driving cars and AI but still struggling with CORS
Normally this would work, but in the case that it doesn’t and you don’t have any access to that domain…
What I did was create a repeater on my server
cURL does not enforce CORS rules. Those rules are enforced by browsers for security purposes.
When you mention that you added the relevant header, I assume you mean you added those headers to the request. Actually, the header is expected in the response headers from the server, indicating that the resource is allowed to be accessed by other websites directly.
FYI, CORS - Cross Origin Resource Sharing. Since your API does not support it, you have two options -
I’d like to vote to close this issue as “Not an issue”.
A Chrome extension helps only for those who have the extension. Depending on Chrome extension in production is not a good idea, as not everyone has that extension.
@adl1995 It did the trick for me 😉
it’s 2019 now, is there any update? 😃
I think this header config will solve this issue.
headers: { 'content-type': 'application/x-www-form-urlencoded' }
Thanks
My solution is to create my own api on my domain server to access any foreign api that doesnt allow cross-origin requests, I call it my repeater api.
Proxy requests using Webpack dev server to avoid cors in development mode
In your webpack.config file add
The above example will proxy the request
axios.post(/api/posts/1 ... . . . .
tohttps://my-target.com/posts/1
The above Git example, u need to change like this in your request
In webpack.config file …
the modified webpack config proxy will change your request like this…
u can use multiple paths in devServer proxy like this In webpack.config file …
Use if u need
I spent hours to fix it and seems like no help everywhere. the simple and fast way is to add a chrome extension called Allow-Control-Allow-Origin*. https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi?hl=en
This is because https://a.4cdn.org and https://boards.4chan.org are considered to be different domains. The difference is in a and boards
@yasincidem - You are an absolute diamond for this suggestion. Cheers - i’ve followed many trails across the web in search of a solution and yours is the first that has worked for my particular scenario.
I was with the same problem and I solve it installing ‘cors’ in my backend (Express).
Run: npm install cors
Then just set this:
I just use jquery’s $.get for external api calls.
There is no option as
crossDomain
inside the Axios. Please study the source-code before giving/using wrong clues.@mddanishyusuf Solution worked for me.
Thanks! 😉
Source : CORS error while making axios.get call
Referring to these answer, i added those lines to my backend express server, like so :
source : CORS on ExpressJS
And everything works fine for me, without any additional configuration on axios or in the frontend, so it’s really not an axios problem but a lack of server side header configuration.
Finally, i think this other answer on stackoverflow, cover pretty well the subject :
hope it helps.
Extraordinary it works !!!
That’s why i said it was a temporary solution. And of course for a dev environment.
There’s no problem with the axios, that’s why the issue was closed. just take a chair and read the article on MDN: https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
南辕北辙,徒劳无功
From here : https://github.com/axios/axios I’ve realized that they doesn’t put full url to axios url request.
So I try and solved this by creating my own API on my site. I just sent request like this
axios.get('/sample/request')
then http://127.0.0.1:8080/sample/request will send another request to https://a.4cdn.org/ and return responses to axios as json.
It’s work for me, hope it can help you
@adl1995 do happen to be able to fix this problem yet? I totally confuse how to handle this error
The whole CORS issue is not Axios, nor even JavaScript itself. It’s a security feature built into most or all browsers. There are ways to ‘hack’ around it, but it’s up to the server to respond with the correct headers.
i use this chrome extension for develop my app https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi
saaaaame
This solution work for me
reference https://stackoverflow.com/questions/42422494/cross-domain-at-axios
I use vue.js (localhost port 8080 ) and Flask for my API (localhost port 5000)
I simply had to make small change in my api code (Flask on port 5000) . I added flask extension flask-CORS and modified my code to use it. Before:
After:
After this it worked and I could use my API. So it is not really axios issue, but API problem and you get warning from Firefox not from calling axios.get function.
No, 😃 It is problems when developing(we use http) when We release on server(we use https) It doesn’t happend. So just install add on: https://chrome.google.com/webstore/detail/allow-control-allow-origi/nlfbmbojpeacfghkpbjhddihlkkiljbi?hl=en
If you using nodejs with express. That post might help you.
If you want only some path to be with cors allowed for instance:
/home/fridge
- not allowed from other origins/home/toilet
- should be allowed from other originsYou can try the following implementation (worked for me)
In routes/home.js
If you don’t use nodejs with express - try googling for
OPTIONS
method requestTested from express: 4.16.3
we encountered this issue as well when switching to axios our setup is webpack + devServer (with proxy) + axios
the problem was that we used our full api url as baseURL in axios instead of just ‘/api’ (the proxy does the mapping via the target attribute)
For those still struggling: Hopefully by now you understand that this isn’t an issue with Axios and the browser is blocking CORS because of a header not being set by the server. If you do understand this and are still having trouble with your own server not setting the headers be sure to set it on your actual web server when using a reverse proxy. For instance, many Node/Express apps are served by NGINX in production with a reverse proxy. See enable-cors.org for how to set it in NGINX.
I don’t think you can resolve CORS directly in axios, because CORS is a browser restriction which is between your browser and target servers.
You can either:
Access-Control-Allow-Origin
in your response headers from your target server.@zacharytyhacz you can’t send browser credentials when the server responds with
Access-Control-Allow-Origin: *
.Either:
*
to be a specific website address....withCredentials: false
in the config/options parameter of the axios request function you’re using.The problem isnot axios, but the API that you’re requesting !
For example I was coded an API in Flask and the GET method was:
But the problem was solved when I add a header in API response:
Then I log my axios response and I get it:
{data: Array(4), status: 200, statusText: "OK", headers: {…}, config: {…}, …}
I dont know what API you all are using but in Flask It was solved !
Ok, after two days of research I finally get it.
Speaking strictly, this is not an axios issue. Actually this must not even be considered an issue. axios was designed to work following all that weird and annoying CORS standards, so the message:
CORS header ‘Access-Control-Allow-Origin’ missing
is expected to happen, thar is the correct working of axios. In the example with the 4chan api, as was said before, the problem is not axios, is the 4chan api itself who is not following the CORS standards.Some people has suggested the old trick of use a proxy to handle7avoid all that headers validations. Here is a blog from Negar Jamalifard exlaining how to do the trick: https://medium.com/js-dojo/how-to-deal-with-cors-error-on-vue-cli-3-d78c024ce8d3 By the way, I am not sure if this can be considered a bad practice.
In my case I was two days trying to connect to a asp net core api in my own localhost until I realize axios, before sending my get request, automatically was sending a “preflight requests” who is sendign as a OPTIONS method which my server was not prepared to handle. If there is someone who blame is to chrome and firefox for display a message so ambiguous.
You need to define ‘Access-Control-Allow-Origin’:
'YOUR_IP:YOUR_PORT'
in the response headers NOT in the request headers.JSONP (JSON with Padding or JSON-P) is used to request data from a server residing in a different domain than the client. JSONP enables sharing of data bypassing same-origin policy.
I ran into this issue when I attempted to simply make a
axios.get()
request to the Darksky weather api. When I read through Darksky’s FAQ page I found a question regarding this same exact problem, they answered by saying that they used this as a security measure to prevent unintended malicious access to their information and suggested creating a proxy to access their database.I made the following change to my
package.json
file (I’m using create-react-app):myKey
was provided to me by Darksky to access their data.This was a super simple fix and worked for me! I would suspect that many api services are going to start using this as a security measure. Hopefully my solution can help others with similar issues.
In summary: create a proxy.
The remote service to which you are making your AJAX request does not accept cross origin AJAX requests from your domain. One thing you could do if you have access to your website server-side codebase, is to create a controller action there (assuming you are using an MVC) and then use it to consume the remote service. You can then make AJAX requests to your controller action. A bonus to this approach is that you could run additional checks before contacting the remote service, formatting its response and even caching it.
Hello everyone, I am just posting this as it took hours for me to solve this.
First of all, CORS is definitely a server-side problem and not client-side but I was more than sure that server code was correct in my case since other apps were working using the same server on different domains. The problem started when I started using
axios
with my custom instance.In my case, it was a very specific problem when we use a
baseURL
inaxios
instance and then try to makeGET
orPOST
calls from anywhere,axios
adds a slash/
betweenbaseURL
and request URL. This makes sense too, but it was the hidden problem. My Laravel server was redirecting to remove the trailing slash which was causing this problem.In general, the pre-flight
OPTIONS
request doesn’t like redirects. If your server is redirecting with301
status code, it might be cached at different levels. So, definitely check for that and avoid it.I hope this might help someone although none of it is a bug.
I was having the same issue on my local. I added cors on my backend and solved. 😃
In my case there was nothing wrong with axios. I just asked the guy who created the API to enable CORS server-side.
Well… you also can try to talk with the dude who create the api you are trying to consume and ask them to fix it.
Why is there no official solution to this problem? I read through this whole thread and am baffled at what seems like a universal problem that no one is really solving in any standard way.
Just use
fetch
to test if server’s cors works first.And…
axios
can request mykoa-server
, but notiris
directly, both of them arms popular cors-middleware.#1358
I managed to solve this using heroku as a proxy.
Here is my code;
What? Really? For me it definitely worked… For the GET method, works like a charm!
Here is the example I made using a public API, based on @ronnin comment:
axios.get('https://world.openfoodfacts.org/api/v0/products', { crossdomain: true }) .then(function (response) { console.log(response.data); })
I had same problem and solved it
worked at first, but then it stopped and i couldnt figure out why.
then I realized that I moved all my code to another file so I need to use router :
trying Vue and axios I obviously got the same issue.
Just tried the solution provided by sundar6445 and it works perfectly. The webpack config file I modified is in <module>/config/index.js. I prefered to modify this one since referenced in <module>/build/webpack.dev.conf.js
In it you find
As described by sundar, change the proxyTable by for instance something like
which means that everything starting by /events will be routed to http://localhost:3000/events. No ‘pathRewrite’ in my case, relative url will be the same.
and of course, don’t forget to remove the full URL in your Vue component. I had:
it becomes:
and it works perfectly well. Thanks to @sundar6445
Hope this helps
Okay, this kinda solved my problem. You see, I’m working with vuejs and Laravel… i set up my Laravel web route in php as follows:
then vuejs file i simply used axios to send a request to my route:
and voila, it works fine.
This is not the issue with the
axios
This is the issue with the backend. I am using Django. And adding these two will solve the issue.Add CORS Middlewear
And allowing the CORS. (Allowing CORS for all)
(This is a bit insecure as it allows all origins. Which will make it vulnurable for CSRF attacks) Hence for production allow only for Specific origins
Example 👍
Yes I’m so much into my shit I really had to check that year shit up 😆
Can confirm, its 2020 and still no update. fetch() has the
mode: 'no-cors'
mode, why axios doesnt just have something similar?I tried
And none of those headers worked. I tried
withCredentials
on both true and false states, didnt work.With fetch, it just works.
What am I supposed to do if I dont want to deal with CORS policy and still use axios? Edit: Plus, why the heck is this issue closed? We obviously still have a problem with this.
Use the following app below to make ur requests working
It worked for me even though the server did not enable CORS
https://cors-anywhere.herokuapp.com/
Usage :
https://cors-anywhere.herokuapp.com${url}
; `Men, who are in trouble, are not well acknowleged with CORS, and should read the article @seungha-kim mentioned earlier: https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
As summary:
as mentions above, I did’t use value * to each Access-Control-Allow-* headers. value *, has many restrictions. a. value * to Access-Control-Allow-Origin,Access-Control-Allow-Headers,Access-Control-Allow-Methods cannot works with Access-Control-Allow-Credentials=true. if cookie is required with request, you’ll need Access-Control-Allow-Credentials=true b. only * is valid, *.google.com is INVALID
Access-Control-Allow-Headers is a list of headers of your request possibly along with. existence of some headers which not listed in it will get you blocked. just check and opt the headers into Access-Control-Allow-Headers
the trouble is mostly not in the client(browser, your client app), but in the server requested resource located.
talk to your server-side dev mate
Hope it’s helpful
in
VueJS
you can create a vile calledvue.config.js
at the root of the project if it doesn’t exist and add something likeThen your
Axios
call should look likeaxios.get('/api/say_hello', {})
if you are running on port 300 and not 3000.
Thank’s @fernandoruch . It works for me when I add it to app.js of my node.js server
If you do it in safari it takes no time, Just enable the developer menu from Preferences >> Advanced, and select “Disable Cross-Origin Restrictions” from the develop menu. If you want local only, then you only need to enable the developer menu, and select “Disable local file restrictions” from the develop menu.
and in Chrome for OSX open Terminal and run:
$ open -a Google\ Chrome --args --disable-web-security --user-data-dir
For Linux run:
$ google-chrome --disable-web-security
Also if you’re trying to access local files for dev purposes like AJAX or JSON, you can use this flag too.-–allow-file-access-from-files
For Windows go into the command prompt and go into the folder where Chrome.exe is and typechrome.exe --disable-web-security
That should disable the same origin policy and allow you to access local files.will help only you, but how about other people?
@PetitBateau I’m not sure how the Chrome extension would help sending requests through axios.
axios.get(‘https://a.4cdn.org/a/threads.json’, { headers: { ‘Access-Control-Allow-Origin’: ‘*’, ‘Access-Control-Allow-Headers’: ‘Content-Type, Authorization’, }, proxy: { host: ‘104.236.174.88’, port: 3128 } }).then(function (response) { console.log('response is : ’ + response.data); }).catch(function (error) { if (error.response) { console.log(error.response.headers); } else if (error.request) { console.log(error.request); } else { console.log(error.message); } console.log(error.config); });
I solved this by the following :
1.create a
vue.config.js
file in the root of the project right beside package.json, containing:2.make a http request like this:
@albertpinto look at all the possible solutions in this mega thread. It’s not a client-side/front-end issue on your end - it is in fact the server (localhost:4000). The server needs to respond with CORS headers to allow the origin.
For example, your server should reply with headers such as:
const board = this.props.routeParams.tag;
axios.get('https://cors-anywhere.herokuapp.com/' + 'https://a.4cdn.org/' + board + '/threads.json', config)
.then(function (response) {
console.log(response.data);
});
I will create a video on how to fix this CORS issue. I will update this comment with a link to my YouTube video.
Edit: https://youtu.be/hxyp_LkKDdk
this was my solution
I had the same problem, after several attempts, testing some solutions, none worked. only after setting the proxy in the package.json. adds: “proxy”: “api address” that it will bypass the cors.
I solved it by not using axios, tried GET from external URLs with $ajax and $get, had no issue with the old jquery stuff. It is a BUG for sure.
The main issue is the difference between server requests and client requests.
When you’re making requests via the client (aka most of the time, a browser) you are at the mercy of the browser software. The standard for browser software is to prevent any attempts at malicious activity that may or may not come from your own software.
If you are making a request from your own server (aka not a browser client), then the given is that for the code you have written yourself, no one (depending on your server settings) can access nor control it, and you know what kinds of requests are outgoing so there are no concerns for network calls occurring outside of your environment or your knowledge.
That’s why browsers are strict about cross origin requests, specifically since once your public code is on the client, you have less control over who sees it / who can manipulate it. In the case that your frontend application is compromised and some malicious software is able to conduct network calls off your code at the expense of your visitors/users, they want to ensure that it cannot happen. Therefore, your mydomain.com cannot make calls to allyourdataarebelongtome.com just in case you didn’t mean for it to happen.
The solution here is not that cross domain requests are not working - it’s that either your own server is preventing this and you need to accommodate this circumstance in accepting your origin domain, or that the third party server you’re trying to make API calls to has some other method of authentication/authorization on top of that cross domain request.
Tried all the solution mentioned above. nothing works. finally found one - https://github.com/expressjs/cors i hope it helps you guys
Somehow useful: https://github.com/shalvah/cors-escape