bkmk

bkmk is a Python library and command-line utility to convert between different bookmarks formats. It has been tested thoroughly on the following formats, and supports conversion between any of them:

• XBEL - a standardised and precisely-defined XML-based format
• Netscape HTML - an imprecisely-defined ad-hoc external interchange format supported by most browsers including Firefox and Chrome, as well as being used internally by Firefox and Mozilla-based browsers
• Chrome JSON - an undocumented format, used internally by Chrome
• bkmk JSON - our own format, which expresses a superset of all the features of all the above formats. The format is extremely simple and will remain stable across many versions of this tool, and files written in it can easily be manipulated using common ecosystem tools such as jq(1). For a detailed specification, see below.

Install via pip:

$ pip3 install -U bkmk

All the functionality of the CLI is mirrored in the API; see bkmk --help or pydoc3 bkmk for details.

CLI examples

Convert to Netscape HTML format, which can be imported into most browsers:

$ bkmk <input-file> backup.html

Directly override Chrome's internal bookmarks JSON. (Do this only when Chrome is closed.)

$ bkmk --fill-special --cull-special -t chrome-json <input-file> ~/.config/chrome/Default/Bookmarks

Retrieve a remote XBEL backup, convert it into bkmk JSON, make sure all elements have IDs, then process it further with jq.

$ curl https://backupserver/bk.xbel | bkmk --fill-ids -f xbel -t bkmk-json | jq <some-complex-script> > <output-file>

API examples

from bkmk import Bookmarks, FORMAT_EXTS

input_filenames = "a.xbel b.xbel".split()
output_filestem = "combined"
output_exts = ".json .html".split()

# combine several bookmark files into one
bk = Bookmarks.new()
for fn in input_filenames:
    with open(fn) as fp:
        bm = Bookmarks.read(fp, "xbel")
        bm.root.name = fn
        bm.prefix_ids(fn.replace(".xbel", "-"))
    bk.root.children.append(bm.root)
# fill in special top-level folders that browsers sometimes expect/require when importing
bk.fill_special()
# fill in timestamps for completeness
bk.fill_timestamps()

# output in several different formats
for o in output_exts:
    with open("%s%s" % (output_filestem, o), "w") as fp:
        bk.write(fp, FORMAT_EXTS[o][0], cull_special=True)

bkmk JSON format spec

The JSON format mirrors our AST type, which is exposed in the public API in the top-level bkmk module, re-exported from bkmk.base.

Meta-documentation. In the below specification,

• unix_micros refers to a JSON integer that represents microseconds since the Unix epoch, ignoring leap seconds, and can be negative.
• string refers to a non-empty JSON string. Attributes that are empty JSON strings are effectively omitted.

Required attributes are in bold, all other attributes are optional.

Specification.

Every object supports the following attributes:

• type: string, possible values separator, bookmark, folder, indicates which further attributes the object may have as defined below.
• id: string, must be unique under the root object, for use as a unique reference by reading tools.
• date_added: unix_micros, when this object was added into the AST.

bookmark, folder additionally support the following attributes:

• name: string, title or short description of this folder or bookmark.
• icon: string, Data URL of the icon for this folder or bookmark.
• date_modified: unix_micros, when this object's attributes were last modified, excluding remote-mirroring attributes such as url_date_modified.

bookmark additionally supports the following attributes:

• url: string, URL target of this bookmark.
• url_date_modified: unix_micros, when the URL target was last modified on the remote side.
• url_date_visited: unix_micros, when the URL target was last visited (retrieved) by the local side.

folder additionally supports the following attributes:

• children: list[object], contents of this folder.
• special: string, possible values TOOLBAR, OTHER_UNFILED, SAVED_TABS, indicates a special status of the folder. On conversion, this is mapped to the corresponding special values of the target format, and treated specially by the target browser.

For interoperability with other formats, we recommend that:

• the root object should have "type": "folder" and no special attribute.
• folders with special attributes should not be placed inside each other. For maximum interoperability they should be immediate children of the root folder - some formats require this, others don't.