Guidelines for self implementing chunked upload to Cloudinary




  • Avatar
    Han BaHwan

    How can I issue `X-Unique-Upload-Id`?
    What's Content-Range format?
    If I understand correctly, this is below:
    `Content-Range: 0-99999/2000000`
    `Content-Range: 100000-199999/2000000`
    `Content-Range: 200000-299999/2000000`

    And how can I handle errors? It looks exception can happen.

  • Avatar
    Nadav Ofir

    For `X-Unique-Upload-Id` you can use any random/unique string generator, for example Unix timestamp.
    `Content-Range` - must contain a preceding "bytes".
    Error messages (bad responses) may arise in case of upload failure. Handling it depends on your use case and the HTTP client you're using.

  • Avatar
    Nadav Ofir

    Han, I've just noticed that the content-range header directions were missing the necessary "bytes" prefix. This is now fixed in the above explanation.

  • Avatar
    Mohamed Habashy

    Hi Everyone,

    I think there is a additional restriction to the mentioned above by Nadav.

    "First chunk must be first. meaning it must arrive the server before any other chunks."

    Then you can do bulk upload the remaining chunk except the last as mentioned above.

    Kind regards,

  • Avatar
    Geoff Plitt

    We are using react-native-fetch-blob:


    'Transfer-Encoding':'Chunked' // <-- CHUNKED header
    {name: 'timestamp', data: timestamp },
    {name: 'signature', data: signature},
    {name: 'eager', data: 'sp_full_hd_wifi/m3u8'},
    {name: 'eager_async', data: 'true'},
    {name: 'api_key', data: cloudinary_config.api_key}
    We got a successful response from Cloudinary.  How do we know whether the upload was actually chunked or just a normal upload?  (I'm using the header marked above as per the documentation but I'm don't know whether it is actually chunking correctly for Cloudinary)
  • Avatar
    Raya Straus

    Hi Geoff,

    If you open a ticket at with more information on your request, we can take a look at our logs. Another option would be to examine the network tab while the upload is being performed. If the upload is chunked you'll be able to see multiple requests going through. 

  • Avatar

    I have trouble implementing this from the browser in javascript. I got the error : 

    { message"Chunk size doesn't match upload size: 6000000 - 8000037" }

    I create my chunks using

    initialFileAsBlob.slice(0, 6000000) 

    to create chunk of 6MB, then I read the chunk with

    chunkToSend = readAsDataUrl(chunk) 

    and send it (with signature) and the following headers : 

    'X-Unique-Upload-Id': 'uniqueid.mp4',
    'Content-Range': 'bytes 0-6000000/17500142

  • Avatar
    Shirly Manor

    It might be because the chunk that you specify is off by 1. when specifying 0-6000000 its mean 6000001.

    If that doesn't help, can you please open a support ticket at for further investigations.


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