A simple parser for the Netscape Bookmark File Format (NBFF), commonly generated by browsers when exporting bookmarks.

It supports parsing into various formats — including customizable structures — and writing the data back.

It also supports merging multiple files.

• Small. Between 260 B and 2 kB (minified + Brotli compressed), with no dependencies.
• Modern. Supports ES modules and tree shaking.
• TypeScript-ready. Full type definitions included.

• Install
• API
  • parse
  • flatParse
  • customParse
  • stringify
  • flatStringify
  • merge
• CLI
  • exclude
  • merge
• Acknowledgments

# npm
npm install nbff-parser

# pnpm
pnpm add nbff-parser

# yarn
yarn add nbff-parser

The parser expects HTML file content to be provided as a string.

Returns bookmark attributes with lowercase names and normalized values.

Type definition

Parses bookmarks into a nested tree structure.

import { parse } from 'nbff-parser'

const bookmarks = parse(html)

{
  "title": "Folder",
  "items": [
    {
      "title": "Bookmark"
    },
    {
      "title": "Nested Folder",
      "items": [
        {
          "title": "Another Bookmark"
        }
      ]
    }
  ]
}

You can configure the output by activating options passed as the second argument.

Type definition

Parses bookmarks into a flat list, where each bookmark includes a folder stack representing its location path. Empty folders are omitted.

import { flatParse } from 'nbff-parser'

const bookmarks = flatParse(html)

[
  {
    "title": "Bookmark",
    "folder": [
      {
        "title": "Folder"
      }
    ]
  },
  {
    "title": "Another Bookmark",
    "folder": [
      {
        "title": "Folder"
      },
      {
        "title": "Nested Folder"
      }
    ]
  }
]

You can configure the output by activating options passed as the second argument.

Type definition

Allows you to define handlers for elements during parsing.

Use this to build custom data structures or implement custom logic.

The methods described above rely on it internally.

import { customParse } from 'nbff-parser'

const handlers = {
  openFolder, // <H1>, <H3>
  addBookmark, // <A>
  describeBookmark, // <DD>
  closeFolder // </DL>
}

const bookmarks = customParse(html, handlers)

Type definition

Converts the parsed tree structure from parse back into an HTML string.

import { parse, stringify } from 'nbff-parser'

const parsed = parse(html)
const stringified = stringify(parsed)
// `stringified` matches the original `html`

Type definition

Converts the flat list from flatParse back into an HTML string.

It requires using flatParse with { withId: true } to ensure unique item IDs.

import { flatParse, flatStringify } from 'nbff-parser'

const parsed = flatParse(html, { withId: true })
const stringified = flatStringify(parsed)
// `stringified` matches the original `html`

Type definition

Merges parsed files into a single HTML string.

import { merge } from 'nbff-parser'

const merged = merge(html1, html2, ...)

CLI methods work with actual files.

Usage:

npx nbff-parser <command> [options]

Removes specified attributes from the HTML file.

Example:

npx nbff-parser exclude \
  file=index.html \
  attrs=add_date,icon \
  output=cleaned.html

Merges multiple files into a single output file.

Example:

npx nbff-parser merge \
  files=foo.html,bar.html \
  output=merged.html

• Netscape Bookmark File Format Wiki for the collected info about NBFF.