AzureStorage.BlobContents

Accessing Data

Returns the content of a blob from Azure Blob Storage as binary.

Syntax

AzureStorage.BlobContents(url as text, optional options as nullable record) as binary

Parameters

Name	Type	Required	Description
`url`	`text`	Yes	The full URL of the blob in Azure Blob Storage (e.g., "https://myaccount.blob.core.windows.net/mycontainer/myfile.csv").
`options`	`record`	No	An optional record to control download behavior. Supported fields include BlockSize, RequestSize, and ConcurrentRequests.

Return Value

binary — The binary content of the specified blob from an Azure storage vault.

Remarks

AzureStorage.BlobContents downloads a single blob from Azure Blob Storage and returns its content as a binary value. The binary result is typically passed to a parser function such as Csv.Document, Json.Document, or Excel.Workbook to interpret the data.

Key options (passed in the options record):

BlockSize (number) -- the number of bytes to read before waiting on the data consumer. Defaults to 4 MB.
RequestSize (number) -- the number of bytes to try to read in a single HTTP request to the server. Defaults to 4 MB.
ConcurrentRequests (number) -- the number of requests to make in parallel for faster downloads. Higher values increase memory usage. Memory required is approximately ConcurrentRequests multiplied by RequestSize. Defaults to 16.

Authentication: Supports Account Key, Shared Access Signature (SAS), Microsoft Account (Azure AD / Entra ID), and Anonymous access. Configure the appropriate credential type in the data source credentials dialog. Do not embed account keys or SAS tokens in the M query.

Query folding: Not applicable. This function downloads the entire blob as a single binary stream. Any filtering or transformation is performed locally after the data is downloaded and parsed.

Platform availability: Available across all Power Query environments including Power BI Desktop, Power BI Service, Excel Desktop, Excel Online, Dataflows, and Fabric Notebooks. No gateway is required for cloud-to-cloud access.

Examples

Example 1: Download a CSV file from Azure Blob Storage

let
    Source = AzureStorage.BlobContents("https://myaccount.blob.core.windows.net/data/sales.csv"),
    Parsed = Csv.Document(Source, [Delimiter = ",", Encoding = TextEncoding.Utf8]),
    Promoted = Table.PromoteHeaders(Parsed, [PromoteAllScalars = true])
in
    Promoted

Example 2: Download a JSON file with increased concurrency

let
    Source = AzureStorage.BlobContents(
        "https://myaccount.blob.core.windows.net/data/records.json",
        [ConcurrentRequests = 32, RequestSize = 8388608]
    ),
    Parsed = Json.Document(Source)
in
    Parsed

Example 3: Download an Excel workbook from Azure Blob Storage

let
    Source = AzureStorage.BlobContents("https://myaccount.blob.core.windows.net/reports/quarterly.xlsx"),
    Workbook = Excel.Workbook(Source, true),
    Sheet1 = Workbook{[Item = "Sheet", Name = "Sheet1"]}[Data]
in
    Sheet1

Compatibility

✓ Power BI Desktop✓ Power BI Service✓ Excel Desktop✓ Excel Online✓ Dataflows✓ Fabric Notebooks