
Notion
Logseq
Joplin
Evernote
Roam Research
Bear
Typora
A second brain, for you, forever. Obsidian is a powerful knowledge base that works on top of a local folder of plain text Markdown files.

Sumnotes
PdfHighlights
Readwise
Zotero
Adobe Acrobat DC
Sumatra PDF
Able2Extract Professional
A local-first web tool to extract PDF highlights, notes, and comments directly into Obsidian, Notion, Markdown, CSV, and JSON. 100% offline and private.

Which is more popular?
Based on our record, Obsidian seems to be more popular. It has been mentioned 1527 times since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | obsidian.md | pdfannotations.com |
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| Platforms | — | |
| Company | Startup from the United States | Startup from the United States · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of Obsidian yet.
What is PDFAnnotations? PDFAnnotations.com is a privacy-first, and browser-local web utility designed to extract highlights, comments, notes, and drawings from PDF files. It formats and exports this extracted data directly into structured notes for personal knowledge management (PKM) tools like...
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
OBSIDIAN: Getting Started, Facts & Pricing
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Obsidian and PDFAnnotations.
PDFAnnotations's answer:
PDFAnnotations is unique because it operates 100% locally in the user's browser using WebAssembly. Unlike traditional extractors that require uploading sensitive documents to cloud servers, PDFAnnotations parses files completely offline. It also features a visual, interactive Template Designer that allows active readers to format their extracted highlights into custom native Markdown, Obsidian Callouts, or Notion blocks with complete metadata preservation.
PDFAnnotations's answer:
A user should choose PDFAnnotations over competitors due to three key advantages: absolute data privacy, extreme cost efficiency, and deep note-taking integration. It requires no signup, no subscriptions, and no file uploads, serving as a robust free/freemium alternative to expensive cloud sync services like Readwise. Additionally, its "Sentence Mode" context preservation, multi-level comment reply extraction, and highly customizable formatting templates are specifically optimized for modern knowledge workers, which generic PDF readers do not support.
PDFAnnotations's answer:
The primary audience of PDFAnnotations consists of students, researchers, academics, legal professionals, and digital note-takers (PKM enthusiasts). It is designed specifically for active readers who frequently annotate academic papers, textbook PDFs, or legal contracts, and need a frictionless, secure way to move those highlighted concepts and reviewer comments into structured personal knowledge bases like Obsidian, Notion, or Logseq.
PDFAnnotations's answer:
PDFAnnotations was born out of frustration. As researchers and avid readers, we found ourselves spending hours manually copying and pasting highlighted quotes and comments from PDF textbooks and research papers into our note-taking apps. Existing cloud-based tools either required expensive monthly subscriptions or forced us to upload confidential PDFs to external servers, violating our data privacy requirements. We decided to build a lightweight, browser-local, WebAssembly-powered tool that solves this friction instantly with zero security risks.
PDFAnnotations's answer:
HTML5, TypeScript, WebAssembly (WASM) for lightning-fast client-side PDF parsing, and Tailwind CSS.
PDFAnnotations's answer:
Share your experience with using Obsidian and PDFAnnotations. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


One thing to note: Notion bills itself as an Evernote competitor for personal users. It can be—but it's too much for most people, and its offline functionality isn't the best. If you love the idea of Notion, go right...
This app is the kind of thing that, if you’re into it, will have you exploring its various ins, outs, and add-ons for days and weeks on end. Obsidian uses the Markdown format for its notes (which means they can be...
However, it's important to note that Obsidian's whiteboard functionality is not as robust as dedicated collaboration tools. While it lacks real-time basic collaboration features, Obsidian compensates with its vibrant...
We have no reviews of PDFAnnotations yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


This is a decision page. Claude Code wrote it after reading a project's notes, and it shows the detail a chat question leaves out. I answer it in Obsidian. - Source: dev.to / 5 days ago
For note-taking, I recommend Obsidian. It's lightweight, has a large community, and offers plenty of useful plugins. I use the Timekeep plugin myself, which helps me connect tasks with the time spent on them. - Source: dev.to / 12 days ago
The setup that makes the output noticeably sharper is a memory layer. Connecting a plain-text notes app like Obsidian (free for personal use) gives the agent durable context: what your project is about, who it is for, and what you have... - Source: dev.to / about 2 months ago
Tracking PDFAnnotations since May 2026.
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Logseq is a local-first, non-linear, outliner notebook for organizing and sharing your personal knowledge base.
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PdfHighlights extracts and exports all your PDF highlights and PDF annotations from all your PDF files into a single report.
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Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
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Effortlessly rediscover and organize your Kindle highlights
Compare Readwise to Obsidian or PDFAnnotations: