chrome.downloads

Description: Use the chrome.downloads API to programmatically initiate, monitor, manipulate, and search for downloads.
Availability: Since Chrome 31.
Permissions: "downloads"

Manifest

You must declare the "downloads" permission in the extension manifest to use this API.

      {
        "name": "My extension",
        ...
        "permissions": [
          "downloads"
        ],
        ...
      }
      

Examples

You can find simple examples of using the chrome.downloads API in the examples/api/downloads directory. For other examples and for help in viewing the source code, see Samples.

Summary

Types
FilenameConflictAction
InterruptReason
DangerType
State
DownloadItem
StringDelta
DoubleDelta
BooleanDelta
Methods
download chrome.downloads.download(object options, function callback)
search chrome.downloads.search(object query, function callback)
pause chrome.downloads.pause(integer downloadId, function callback)
resume chrome.downloads.resume(integer downloadId, function callback)
cancel chrome.downloads.cancel(integer downloadId, function callback)
getFileIcon chrome.downloads.getFileIcon(integer downloadId, object options, function callback)
open chrome.downloads.open(integer downloadId)
show chrome.downloads.show(integer downloadId)
showDefaultFolder chrome.downloads.showDefaultFolder()
erase chrome.downloads.erase(object query, function callback)
removeFile chrome.downloads.removeFile(integer downloadId, function callback)
acceptDanger chrome.downloads.acceptDanger(integer downloadId, function callback)
drag chrome.downloads.drag(integer downloadId)
setShelfEnabled chrome.downloads.setShelfEnabled(boolean enabled)
Events
onCreated
onErased
onChanged
onDeterminingFilename

Types

FilenameConflictAction

uniquify
To avoid duplication, the filename is changed to include a counter before the filename extension.
overwrite
The existing file will be overwritten with the new file.
prompt
The user will be prompted with a file chooser dialog.
Enum
"uniquify", "overwrite", or "prompt"

InterruptReason

Enum
"FILE_FAILED", "FILE_ACCESS_DENIED", "FILE_NO_SPACE", "FILE_NAME_TOO_LONG", "FILE_TOO_LARGE", "FILE_VIRUS_INFECTED", "FILE_TRANSIENT_ERROR", "FILE_BLOCKED", "FILE_SECURITY_CHECK_FAILED", "FILE_TOO_SHORT", "NETWORK_FAILED", "NETWORK_TIMEOUT", "NETWORK_DISCONNECTED", "NETWORK_SERVER_DOWN", "NETWORK_INVALID_REQUEST", "SERVER_FAILED", "SERVER_NO_RANGE", "SERVER_PRECONDITION", "SERVER_BAD_CONTENT", "SERVER_UNAUTHORIZED", "SERVER_CERT_PROBLEM", "SERVER_FORBIDDEN", "USER_CANCELED", "USER_SHUTDOWN", or "CRASH"

DangerType

file
The download's filename is suspicious.
url
The download's URL is known to be malicious.
content
The downloaded file is known to be malicious.
uncommon
The download's URL is not commonly downloaded and could be dangerous.
host
The download came from a host known to distribute malicious binaries and is likely dangerous.
unwanted
The download is potentially unwanted or unsafe. E.g. it could make changes to browser or computer settings.
safe
The download presents no known danger to the user's computer.
accepted
The user has accepted the dangerous download.
Enum
"file", "url", "content", "uncommon", "host", "unwanted", "safe", or "accepted"

State

in_progress
The download is currently receiving data from the server.
interrupted
An error broke the connection with the file host.
complete
The download completed successfully.
Enum
"in_progress", "interrupted", or "complete"

DownloadItem

properties
integer id

An identifier that is persistent across browser sessions.

string url

Absolute URL.

string referrer

Absolute URL.

string filename

Absolute local path.

boolean incognito

False if this download is recorded in the history, true if it is not recorded.

DangerType danger

Indication of whether this download is thought to be safe or known to be suspicious.

string mime

The file's MIME type.

string startTime

The time when the download began in ISO 8601 format. May be passed directly to the Date constructor: chrome.downloads.search({}, function(items){items.forEach(function(item){console.log(new Date(item.startTime))})})

string (optional) endTime

The time when the download ended in ISO 8601 format. May be passed directly to the Date constructor: chrome.downloads.search({}, function(items){items.forEach(function(item){if (item.endTime) console.log(new Date(item.endTime))})})

string (optional) estimatedEndTime

Estimated time when the download will complete in ISO 8601 format. May be passed directly to the Date constructor: chrome.downloads.search({}, function(items){items.forEach(function(item){if (item.estimatedEndTime) console.log(new Date(item.estimatedEndTime))})})

State state

Indicates whether the download is progressing, interrupted, or complete.

boolean paused

True if the download has stopped reading data from the host, but kept the connection open.

boolean canResume

True if the download is in progress and paused, or else if it is interrupted and can be resumed starting from where it was interrupted.

InterruptReason (optional) error

Why the download was interrupted. Several kinds of HTTP errors may be grouped under one of the errors beginning with SERVER_. Errors relating to the network begin with NETWORK_, errors relating to the process of writing the file to the file system begin with FILE_, and interruptions initiated by the user begin with USER_.

double bytesReceived

Number of bytes received so far from the host, without considering file compression.

double totalBytes

Number of bytes in the whole file, without considering file compression, or -1 if unknown.

double fileSize

Number of bytes in the whole file post-decompression, or -1 if unknown.

boolean exists

Whether the downloaded file still exists. This information may be out of date because Chrome does not automatically watch for file removal. Call search() in order to trigger the check for file existence. When the existence check completes, if the file has been deleted, then an onChanged event will fire. Note that search() does not wait for the existence check to finish before returning, so results from search() may not accurately reflect the file system. Also, search() may be called as often as necessary, but will not check for file existence any more frequently than once every 10 seconds.

string (optional) byExtensionId

The identifier for the extension that initiated this download if this download was initiated by an extension. Does not change once it is set.

string (optional) byExtensionName

The localized name of the extension that initiated this download if this download was initiated by an extension. May change if the extension changes its name or if the user changes their locale.

StringDelta

properties
string (optional) previous
string (optional) current

DoubleDelta

Since Chrome 34.

properties
double (optional) previous
double (optional) current

BooleanDelta

properties
boolean (optional) previous
boolean (optional) current

Methods

download

chrome.downloads.download(object options, function callback)

Download a URL. If the URL uses the HTTP[S] protocol, then the request will include all cookies currently set for its hostname. If both filename and saveAs are specified, then the Save As dialog will be displayed, pre-populated with the specified filename. If the download started successfully, callback will be called with the new DownloadItem's downloadId. If there was an error starting the download, then callback will be called with downloadId=undefined and runtime.lastError will contain a descriptive string. The error strings are not guaranteed to remain backwards compatible between releases. Extensions must not parse it.

Parameters
object options

What to download and how.

string url

The URL to download.

string (optional) filename

A file path relative to the Downloads directory to contain the downloaded file, possibly containing subdirectories. Absolute paths, empty paths, and paths containing back-references ".." will cause an error. onDeterminingFilename allows suggesting a filename after the file's MIME type and a tentative filename have been determined.

FilenameConflictAction (optional) conflictAction

The action to take if filename already exists.

boolean (optional) saveAs

Use a file-chooser to allow the user to select a filename regardless of whether filename is set or already exists.

enum of "GET", or "POST" (optional) method

The HTTP method to use if the URL uses the HTTP[S] protocol.

array of object (optional) headers

Extra HTTP headers to send with the request if the URL uses the HTTP[s] protocol. Each header is represented as a dictionary containing the keys name and either value or binaryValue, restricted to those allowed by XMLHttpRequest.

Properties of each object

string name

Name of the HTTP header.

string value

Value of the HTTP header.

string (optional) body

Post body.

function (optional) callback

Called with the id of the new DownloadItem.

If you specify the callback parameter, it should be a function that looks like this:

function(integer downloadId) {...};
integer downloadId
chrome.downloads.search(object query, function callback)

Find DownloadItem. Set query to the empty object to get all DownloadItem. To get a specific DownloadItem, set only the id field. To page through a large number of items, set orderBy: ['-startTime'], set limit to the number of items per page, and set startedAfter to the startTime of the last item from the last page.

Parameters
object query
array of string (optional) query

This array of search terms limits results to DownloadItem whose filename or url contain all of the search terms that do not begin with a dash '-' and none of the search terms that do begin with a dash.

string (optional) startedBefore

Limits results to DownloadItem that started before the given ms since the epoch.

string (optional) startedAfter

Limits results to DownloadItem that started after the given ms since the epoch.

string (optional) endedBefore

Limits results to DownloadItem that ended before the given ms since the epoch.

string (optional) endedAfter

Limits results to DownloadItem that ended after the given ms since the epoch.

double (optional) totalBytesGreater

Limits results to DownloadItem whose totalBytes is greater than the given integer.

double (optional) totalBytesLess

Limits results to DownloadItem whose totalBytes is less than the given integer.

string (optional) filenameRegex

Limits results to DownloadItem whose filename matches the given regular expression.

string (optional) urlRegex

Limits results to DownloadItem whose url matches the given regular expression.

integer (optional) limit

The maximum number of matching DownloadItem returned. Defaults to 1000. Set to 0 in order to return all matching DownloadItem. See search for how to page through results.

array of string (optional) orderBy

Set elements of this array to DownloadItem properties in order to sort search results. For example, setting orderBy=['startTime'] sorts the DownloadItem by their start time in ascending order. To specify descending order, prefix with a hyphen: '-startTime'.

integer (optional) id

The id of the DownloadItem to query.

string (optional) url

Absolute URL.

string (optional) filename

Absolute local path.

DangerType (optional) danger

Indication of whether this download is thought to be safe or known to be suspicious.

string (optional) mime

The file's MIME type.

string (optional) startTime

The time when the download began in ISO 8601 format.

string (optional) endTime

The time when the download ended in ISO 8601 format.

State (optional) state

Indicates whether the download is progressing, interrupted, or complete.

boolean (optional) paused

True if the download has stopped reading data from the host, but kept the connection open.

InterruptReason (optional) error

Why a download was interrupted.

double (optional) bytesReceived

Number of bytes received so far from the host, without considering file compression.

double (optional) totalBytes

Number of bytes in the whole file, without considering file compression, or -1 if unknown.

double (optional) fileSize

Number of bytes in the whole file post-decompression, or -1 if unknown.

boolean (optional) exists

Whether the downloaded file exists;

function callback

The callback parameter should be a function that looks like this:

function(array of DownloadItem results) {...};
array of DownloadItem results

pause

chrome.downloads.pause(integer downloadId, function callback)

Pause the download. If the request was successful the download is in a paused state. Otherwise runtime.lastError contains an error message. The request will fail if the download is not active.

Parameters
integer downloadId

The id of the download to pause.

function (optional) callback

Called when the pause request is completed.

If you specify the callback parameter, it should be a function that looks like this:

function() {...};

resume

chrome.downloads.resume(integer downloadId, function callback)

Resume a paused download. If the request was successful the download is in progress and unpaused. Otherwise runtime.lastError contains an error message. The request will fail if the download is not active.

Parameters
integer downloadId

The id of the download to resume.

function (optional) callback

Called when the resume request is completed.

If you specify the callback parameter, it should be a function that looks like this:

function() {...};

cancel

chrome.downloads.cancel(integer downloadId, function callback)

Cancel a download. When callback is run, the download is cancelled, completed, interrupted or doesn't exist anymore.

Parameters
integer downloadId

The id of the download to cancel.

function (optional) callback

Called when the cancel request is completed.

If you specify the callback parameter, it should be a function that looks like this:

function() {...};

getFileIcon

chrome.downloads.getFileIcon(integer downloadId, object options, function callback)

Retrieve an icon for the specified download. For new downloads, file icons are available after the onCreated event has been received. The image returned by this function while a download is in progress may be different from the image returned after the download is complete. Icon retrieval is done by querying the underlying operating system or toolkit depending on the platform. The icon that is returned will therefore depend on a number of factors including state of the download, platform, registered file types and visual theme. If a file icon cannot be determined, runtime.lastError will contain an error message.

Parameters
integer downloadId

The identifier for the download.

object (optional) options
integer (optional) size

The size of the returned icon. The icon will be square with dimensions size * size pixels. The default and largest size for the icon is 32x32 pixels. The only supported sizes are 16 and 32. It is an error to specify any other size.

function callback

A URL to an image that represents the download.

The callback parameter should be a function that looks like this:

function(string iconURL) {...};
string (optional) iconURL

open

chrome.downloads.open(integer downloadId)

Open the downloaded file now if the DownloadItem is complete; otherwise returns an error through runtime.lastError. Requires the "downloads.open" permission in addition to the "downloads" permission. An onChanged event will fire when the item is opened for the first time.

Parameters
integer downloadId

The identifier for the downloaded file.

show

chrome.downloads.show(integer downloadId)

Show the downloaded file in its folder in a file manager.

Parameters
integer downloadId

The identifier for the downloaded file.

showDefaultFolder

chrome.downloads.showDefaultFolder()

Show the default Downloads folder in a file manager.

erase

chrome.downloads.erase(object query, function callback)

Erase matching DownloadItem from history without deleting the downloaded file. An onErased event will fire for each DownloadItem that matches query, then callback will be called.

Parameters
object query
array of string (optional) query

This array of search terms limits results to DownloadItem whose filename or url contain all of the search terms that do not begin with a dash '-' and none of the search terms that do begin with a dash.

string (optional) startedBefore

Limits results to DownloadItem that started before the given ms since the epoch.

string (optional) startedAfter

Limits results to DownloadItem that started after the given ms since the epoch.

string (optional) endedBefore

Limits results to DownloadItem that ended before the given ms since the epoch.

string (optional) endedAfter

Limits results to DownloadItem that ended after the given ms since the epoch.

double (optional) totalBytesGreater

Limits results to DownloadItem whose totalBytes is greater than the given integer.

double (optional) totalBytesLess

Limits results to DownloadItem whose totalBytes is less than the given integer.

string (optional) filenameRegex

Limits results to DownloadItem whose filename matches the given regular expression.

string (optional) urlRegex

Limits results to DownloadItem whose url matches the given regular expression.

integer (optional) limit

The maximum number of matching DownloadItem returned. Defaults to 1000. Set to 0 in order to return all matching DownloadItem. See search for how to page through results.

array of string (optional) orderBy

Set elements of this array to DownloadItem properties in order to sort search results. For example, setting orderBy=['startTime'] sorts the DownloadItem by their start time in ascending order. To specify descending order, prefix with a hyphen: '-startTime'.

integer (optional) id

The id of the DownloadItem to query.

string (optional) url

Absolute URL.

string (optional) filename

Absolute local path.

DangerType (optional) danger

Indication of whether this download is thought to be safe or known to be suspicious.

string (optional) mime

The file's MIME type.

string (optional) startTime

The time when the download began in ISO 8601 format.

string (optional) endTime

The time when the download ended in ISO 8601 format.

State (optional) state

Indicates whether the download is progressing, interrupted, or complete.

boolean (optional) paused

True if the download has stopped reading data from the host, but kept the connection open.

InterruptReason (optional) error

Why a download was interrupted.

double (optional) bytesReceived

Number of bytes received so far from the host, without considering file compression.

double (optional) totalBytes

Number of bytes in the whole file, without considering file compression, or -1 if unknown.

double (optional) fileSize

Number of bytes in the whole file post-decompression, or -1 if unknown.

boolean (optional) exists

Whether the downloaded file exists;

function (optional) callback

If you specify the callback parameter, it should be a function that looks like this:

function(array of integer erasedIds) {...};
array of integer erasedIds

removeFile

chrome.downloads.removeFile(integer downloadId, function callback)

Remove the downloaded file if it exists and the DownloadItem is complete; otherwise return an error through runtime.lastError.

Parameters
integer downloadId
function (optional) callback

If you specify the callback parameter, it should be a function that looks like this:

function() {...};

acceptDanger

chrome.downloads.acceptDanger(integer downloadId, function callback)

Prompt the user to accept a dangerous download. Can only be called from a visible context (tab, window, or page/browser action popup). Does not automatically accept dangerous downloads. If the download is accepted, then an onChanged event will fire, otherwise nothing will happen. When all the data is fetched into a temporary file and either the download is not dangerous or the danger has been accepted, then the temporary file is renamed to the target filename, the |state| changes to 'complete', and onChanged fires.

Parameters
integer downloadId

The identifier for the DownloadItem.

function (optional) callback

Called when the danger prompt dialog closes.

If you specify the callback parameter, it should be a function that looks like this:

function() {...};

drag

chrome.downloads.drag(integer downloadId)

Initiate dragging the downloaded file to another application. Call in a javascript ondragstart handler.

Parameters
integer downloadId

setShelfEnabled

chrome.downloads.setShelfEnabled(boolean enabled)

Enable or disable the gray shelf at the bottom of every window associated with the current browser profile. The shelf will be disabled as long as at least one extension has disabled it. Enabling the shelf while at least one other extension has disabled it will return an error through runtime.lastError. Requires the "downloads.shelf" permission in addition to the "downloads" permission.

Parameters
boolean enabled

Events

onCreated

This event fires with the DownloadItem object when a download begins.

addListener

chrome.downloads.onCreated.addListener(function callback)
Parameters
function callback

The callback parameter should be a function that looks like this:

function( DownloadItem downloadItem) {...};
DownloadItem downloadItem

onErased

Fires with the downloadId when a download is erased from history.

addListener

chrome.downloads.onErased.addListener(function callback)
Parameters
function callback

The callback parameter should be a function that looks like this:

function(integer downloadId) {...};
integer downloadId

The id of the DownloadItem that was erased.

onChanged

When any of a DownloadItem's properties except bytesReceived and estimatedEndTime changes, this event fires with the downloadId and an object containing the properties that changed.

addListener

chrome.downloads.onChanged.addListener(function callback)
Parameters
function callback

The callback parameter should be a function that looks like this:

function(object downloadDelta) {...};
object downloadDelta
integer id

The id of the DownloadItem that changed.

StringDelta (optional) url

The change in url, if any.

StringDelta (optional) filename

The change in filename, if any.

StringDelta (optional) danger

The change in danger, if any.

StringDelta (optional) mime

The change in mime, if any.

StringDelta (optional) startTime

The change in startTime, if any.

StringDelta (optional) endTime

The change in endTime, if any.

StringDelta (optional) state

The change in state, if any.

BooleanDelta (optional) canResume

The change in canResume, if any.

BooleanDelta (optional) paused

The change in paused, if any.

StringDelta (optional) error

The change in error, if any.

DoubleDelta (optional) totalBytes

The change in totalBytes, if any.

DoubleDelta (optional) fileSize

The change in fileSize, if any.

BooleanDelta (optional) exists

The change in exists, if any.

onDeterminingFilename

During the filename determination process, extensions will be given the opportunity to override the target DownloadItem.filename. Each extension may not register more than one listener for this event. Each listener must call suggest exactly once, either synchronously or asynchronously. If the listener calls suggest asynchronously, then it must return true. If the listener neither calls suggest synchronously nor returns true, then suggest will be called automatically. The DownloadItem will not complete until all listeners have called suggest. Listeners may call suggest without any arguments in order to allow the download to use downloadItem.filename for its filename, or pass a suggestion object to suggest in order to override the target filename. If more than one extension overrides the filename, then the last extension installed whose listener passes a suggestion object to suggest wins. In order to avoid confusion regarding which extension will win, users should not install extensions that may conflict. If the download is initiated by download and the target filename is known before the MIME type and tentative filename have been determined, pass filename to download instead.

addListener

chrome.downloads.onDeterminingFilename.addListener(function callback)
Parameters
function callback

The callback parameter should be a function that looks like this:

function( DownloadItem downloadItem, function suggest) {...};
DownloadItem downloadItem
function suggest

The suggest parameter should be a function that looks like this:

function(object suggestion) {...};
object (optional) suggestion
string filename

The DownloadItem's new target DownloadItem.filename, as a path relative to the user's default Downloads directory, possibly containing subdirectories. Absolute paths, empty paths, and paths containing back-references ".." will be ignored.

FilenameConflictAction (optional) conflictAction

The action to take if filename already exists.