What to look for
Start with the extension itself. Chrome's own Bookmark Manager covers folders, sorting and address-bar search, so an extension must add something Chrome does not do (Chrome Help).
Then check three things: whether the tool exports your data in an open format such as the Netscape HTML bookmark file Chrome itself uses (Chrome Help), whether it works only as an extension or also has apps and a web app, and whether you want a hosted service or software you run yourself.
Raindrop.io
Raindrop calls itself an "All-in-one bookmark manager" and offers a Chrome extension plus apps for Windows, Mac, iPad, iPhone and Android (official overview).
The free tier has no stated caps on bookmarks, collections, highlights or devices, with a 100 MB per month file upload allowance (Pro page). Pro prices are not stated here. Raindrop also documents an MCP integration.
Linkwarden
Linkwarden is a "Self-hosted collaborative bookmark manager to collect, read, annotate, and fully preserve what matters", under the AGPL-3.0 licence (repository).
It has a browser extension, native iOS and Android apps, full-text search with filter and sort, SingleFile uploads and Floccus sync. Self-hosting is free but you deploy and maintain it; a cloud offering exists, and its price is not stated here (repository).
Karakeep
Karakeep is a self-hostable "bookmark-everything app" for links, notes and images with AI-based automatic tagging and full-text search, under AGPL-3.0 (repository).
Its platform list includes a Chrome extension linking to the Chrome Web Store, plus iOS, Android and web (platform details). Importers cover Chrome, Pocket, Linkwarden, Omnivore and Tab Session Manager (repository).
Linkding
Linkding is a "minimal, fast" self-hosted bookmark manager set up with Docker, under the MIT licence (repository).
It offers extensions for Chrome and Firefox plus a bookmarklet, and imports and exports bookmarks in Netscape HTML format. Managed hosting options exist with no prices stated (repository).
Readwise Reader
Readwise Reader is a read-it-later app rather than a plain bookmark manager. Its browser extension covers Chrome, Firefox and Safari, and it saves full articles, PDFs, EPUBs, newsletters, RSS feeds, YouTube videos and X threads (product page).
Import accepts an Instapaper library, a Pocket export file, a URL CSV and OPML; export covers CSV, OPML, ZIP and Markdown highlights (product page). Pricing runs $9.99 per month billed annually or $12.99 billed monthly for the full Readwise subscription, with a 30-day free trial (product page).
Toby
Toby's site lists Spaces, Collections, Smart Sort, Save Sessions, and Chrome, Firefox and Edge support (vendor site).
The site says "Free to try". Tier prices, import and export details are not stated here.
OneTab
OneTab converts open tabs into a list you can restore one by one or all at once, with folders, tasks and notes, and encrypted cross-browser sync. Its vendor comparison claims up to 95% memory saving (vendor site).
Core use needs no signup or registration. Export and import of tab lists are stated; file formats and pricing are not stated here (vendor site).
Workona
Workona is a tab manager for Chrome, Edge and Firefox with spaces per project, autosave, cloud backup, cross-device sync, tab suspend and search (vendor site).
Its price is not stated here.
Tab managers versus bookmark managers
OneTab and Workona are tab managers: OneTab turns open tabs into a list (vendor site), and Workona organizes tabs into per-project spaces (vendor site).
Bookmark managers such as Raindrop and Linkding hold saved links over time, across browsing sessions, with collections or folders (Raindrop, Linkding). If your problem is too many open tabs right now, a tab manager fits. If your problem is finding a page again next month, a bookmark manager fits.
KnowMan extension
The KnowMan extension is listed on the Chrome Web Store as "KnowMan - Save to Read Later" (Chrome Web Store).
Per the store description, it saves articles, organizes them with tags for reading later, and offers one-click saving from any webpage (Chrome Web Store). The store page did not show a price.
Which to pick
For visual collections on a free tier, choose Raindrop. For self-hosting, choose Karakeep, Linkwarden or Linkding. For reading saved articles, choose Readwise Reader. For tab overload rather than long-term links, consider OneTab or Workona. For saving pages and asking questions about them, consider KnowMan.
Questions people ask
Is Chrome's built-in Bookmark Manager enough?
It handles folders, sorting, address-bar search with @bookmarks, and HTML import and export. Pick an extension when you need what Chrome does not offer, such as collections, tagging or cross-browser sync (Chrome Help, export help).
Which extensions work outside Chrome?
Raindrop lists Firefox, Safari and Edge extensions plus mobile apps (overview). Readwise Reader covers Firefox and Safari (product page). Linkding offers Firefox and Chrome extensions (repository).
What does the KnowMan Chrome extension do?
The store listing says it saves articles, organizes with tags for reading later, and saves any webpage with one click (Chrome Web Store).