10 Best PDF Markup Software Options in 2026 (Free and Paid)

The best PDF markup software in 2026 depends on what you already own: Apple Preview handles highlights and comments for free on a Mac, Adobe Acrobat Reader does the same on Windows, and paid tools like Acrobat Pro, PDF Expert, and Foxit earn their price once you need stamps, shared review workflows, or edits to the underlying text. Below are ten options, four genuinely free, six paid, with the honest drawbacks of each, plus the two things people skip when comparing tools like this: whether a “redacted” section is actually removed or just visually covered, and whether the app you pick can handle a large file smoothly on the device you actually use it on. If you only mark up a contract once a month, do not pay for anything.

Quick comparison first, then the details.

Tool	Best for	Free option	Standout feature
Apple Preview	Mac users with basic needs	Yes (built into macOS)	Zero setup, instant markup toolbar
Adobe Acrobat Reader	Windows users, standard annotations	Yes	Comments sync with Acrobat Pro reviewers
PDF24	Occasional markup without an account	Yes (fully free)	No sign-up, no watermarks, no limits
Xodo	Cross-platform annotation on a budget	Free plan	Annotates on web, mobile, and desktop
Adobe Acrobat Pro	Teams running formal review cycles	Trial only	Shared reviews with tracked responses
PDF Expert	Mac and iPad power users	Limited free version	Fast rendering on large files
Foxit PDF Editor	Businesses avoiding Adobe pricing	Free Foxit Reader for basics	Familiar ribbon interface, lighter footprint
Drawboard PDF	Pen and tablet users, drawing review	Limited free tier	Pressure-sensitive ink built for styluses
Lumin	Teams working out of Google Drive	Free plan	Live collaborative annotation in the browser
Smallpdf	Quick one-off jobs in a browser	Free with daily limits	21 PDF tools behind one clean interface

How to choose PDF markup software

Two questions settle most of the decision.

First: do you need to change the PDF or just comment on it? Highlighting, sticky notes, stamps, and freehand ink are annotation, and every tool on this list does that. Rewriting a paragraph or swapping an image is editing, and that is where free tools stop and Acrobat Pro or Foxit start earning money.

Second: does anyone else need to see your markup? A markup layer only matters if the next person can open it. Standard PDF annotations travel well between Acrobat, Preview, Xodo, and Foxit, but proprietary review features, Drawboard’s document collaboration or Lumin’s live comments among them, only work when both sides use the same tool.

One warning from experience: some web tools flatten annotations when they export, which turns your editable comments into baked-in pixels. If a reviewer needs to reply to your notes, test a round trip before you commit.

Free PDF markup software

1. Apple Preview

Preview ships with every Mac, and most Mac owners underestimate it. Open a PDF, click the markup pencil, and you get highlights, shapes, text boxes, a signature tool, and freehand drawing.

• Highlight, underline, and strikethrough from the selection popover
• Notes that collapse into small squares and expand on click
• Signature capture via trackpad or iPhone camera
• Shape and arrow tools with adjustable colors
• Page management: reorder, rotate, and merge PDFs by dragging thumbnails

Best for: Mac users who need everyday markup without installing anything.

Drawback: Comment handling is thin. There is no comment list or reply threading, so a document with forty notes becomes a scavenger hunt. Windows users are out entirely.

2. Adobe Acrobat Reader

The free Reader gets confused with paid Acrobat constantly, so to be clear: Reader annotates PDFs at no cost. Highlights, sticky notes, drawing tools, stamps, and text boxes are all included; it is editing the PDF’s actual content that requires Pro.

• Full standard annotation set that every other PDF app can read
• Comment pane listing every note with author and timestamp
• Reply threads on comments, useful for back-and-forth review
• Stamps including Approved, Draft, and custom images
• Fill and sign for forms, free

Best for: Anyone reviewing documents with people who live in the Adobe ecosystem.

Drawback: The app pushes Pro upgrades hard. Expect upsell buttons where features used to be, and a heavier install than a reader should need.

3. PDF24

PDF24 is a free toolbox from a German company that makes money on enterprise products, which explains the part people do not believe: no watermarks, no page limits, no account required. The annotation tool runs in your browser or as a Windows desktop app.

• Highlighting, freehand drawing, shapes, and text annotations
• Runs locally in the desktop version, so files stay on your machine
• Merge, split, compress, and convert alongside markup
• No registration for any tool

Best for: Occasional users who refuse to create yet another account.

Drawback: The interface is utilitarian and the annotation feature set is shallow. There is no comment threading, no stamps library, and nothing built for multi-reviewer workflows.

4. Xodo

Xodo started as a beloved free mobile annotator and now runs on web, Windows, Mac, iOS, and Android. The free plan still covers annotation well; the paid tier gates conversion and editing tools.

• Standard-compliant annotations that survive opening in Acrobat
• Genuinely good tablet experience with finger and stylus input
• Night mode and tabbed reading for long review sessions
• Works offline on mobile once a file is downloaded

Best for: People who mark up PDFs on a phone or tablet as often as on a desktop.

Drawback: Since the move to a freemium model, the app nags about upgrades, and features that used to be free have migrated behind the paywall. Check what is included before relying on it.

Paid PDF markup software

5. Adobe Acrobat Pro

Acrobat Pro is the tool the other nine are measured against. For pure markup it is overkill; for running a review with five stakeholders, a legal sign-off, and a deadline, it is the standard for a reason. Pricing is subscription-based, billed per user.

• Shared reviews: send one link, collect everyone’s comments in one file
• Comment summaries exportable as a separate report
• Full text and image editing inside the PDF
• Redaction that actually removes content instead of drawing a black box over it
• Compare versions to see what changed between drafts

Best for: Teams with formal review cycles and compliance requirements.

Drawback: The subscription cost stings for individuals, and Adobe makes cancellation famously annoying. Annual plans billed monthly carry an early termination fee.

6. PDF Expert

PDF Expert by Readdle is what Acrobat would feel like if it were built by a small team that cared about speed. It is Mac, iPhone, and iPad only. A 500-page scanned document that makes other apps stutter scrolls smoothly here.

• Annotation toolbar you can customize with your five most-used tools
• Excellent Apple Pencil support with palm rejection
• Text editing, page management, and form filling in the paid tier
• Reads and writes standard annotations, so Acrobat users see your notes
• Syncs documents across Mac and iPad

Best for: Apple-only professionals who mark up documents daily and feel Preview’s limits.

Drawback: No Windows or Android version, which rules it out for mixed-platform teams. Pricing is subscription-based, a sore point for users who bought the old one-time license.

7. Foxit PDF Editor

Foxit is the most common answer to “Acrobat, but cheaper.” The interface mimics Microsoft Office’s ribbon, so nobody needs training, and the annotation tools cover everything a business reviewer expects. The free Foxit PDF Reader handles basic commenting and annotation if you do not need editing, and Foxit’s Smart Redact feature on the paid editor uses AI-assisted detection to find sensitive content before you black it out.

• Complete annotation set: highlights, callouts, stamps, measurements
• Shared review workflows comparable to Acrobat’s
• Text editing with decent reflow when you add or delete sentences
• Lighter install and faster launch than Acrobat
• Available on Windows, Mac, and mobile

Best for: Businesses that want Acrobat-level review features without Adobe’s per-seat pricing.

Drawback: Advanced features trail Adobe. Redaction and accessibility tooling exist but feel a generation behind, and the mobile apps are weaker than the desktop version.

8. Drawboard PDF

Drawboard built its reputation with engineers and architects reviewing drawings on Surface tablets, and it is still the best program to markup PDFs with a pen. Ink feels immediate, and the tools assume you are drawing, not typing. A free tier is available; the useful features sit in the subscription.

• Pressure-sensitive ink with adjustable smoothing
• Measurement and calibration tools for scaled drawings
• Grid and line templates as overlays
• Document merging and page reorganization
• Radial menu designed for pen-first use

Best for: Anyone reviewing technical drawings with a stylus.

Drawback: The move from a one-time purchase to subscription pricing angered long-time users, and the free tier keeps shrinking. Keyboard-and-mouse users get little benefit over cheaper options.

9. Lumin

Lumin is browser-based markup with real-time collaboration, several people annotating the same PDF at once, Google Docs style. It plugs directly into Google Drive and Google Classroom, which is why schools adopted it in numbers. A free plan is available; team features are paid per user.

• Live multi-user annotation with visible cursors
• Opens PDFs straight from Google Drive and saves back automatically
• Comments, highlights, shapes, and signature tools in the browser
• Team spaces for organizing shared documents

Best for: Teams and classrooms already living in Google Workspace.

Drawback: It needs an internet connection to be useful, and heavy PDFs render slower in a browser tab than in any native app on this list.

10. Smallpdf

Smallpdf is a Swiss web platform bundling twenty-one PDF tools, annotate, compress, convert, sign, merge among them, behind one of the cleanest interfaces in the category. The free tier limits how many tasks you can run per day; the paid plan removes the caps and adds batch processing.

• Annotation tool with highlights, text, shapes, and freehand drawing
• E-signature requests included in paid plans
• Desktop and mobile apps alongside the web version
• Conversion between PDF and Office formats

Best for: People whose PDF needs are occasional and varied, annotate today, compress tomorrow.

Drawback: Markup depth is limited. There is no comment threading or review workflow, so it suits one-off jobs, not document review with a team.

Security and Redaction: The Feature Most People Ignore Until It Matters

Annotation gets all the attention in a roundup like this, but redaction is where a wrong assumption actually hurts you. A black rectangle drawn over text with a basic annotation tool does not remove the underlying text; it just covers it visually, and that text is often still selectable, searchable, or recoverable by anyone who copies the content out of the “redacted” area. This has caused real, public data leaks when organizations shared documents they believed were properly redacted.

Only a handful of tools on this list do true redaction, meaning the underlying content is actually deleted rather than covered. Adobe Acrobat Pro and Foxit PDF Editor both offer genuine redaction tools built for this specifically, and Foxit’s Smart Redact goes a step further by using AI to flag likely sensitive content, social security numbers, phone numbers, email addresses, before you manually confirm what to remove. If a document you are marking up contains anything genuinely sensitive, client data, legal case details, financial records, confirm your tool does real redaction before you rely on a black box to hide it. Free annotation tools without a dedicated redaction feature should not be trusted with that job.

Mobile and Tablet Markup: What Actually Works With a Finger or a Pen

Desktop annotation and mobile annotation are different skills for a tool to get right, and plenty of otherwise good desktop apps have mediocre mobile companions. If most of your markup happens on a phone or tablet rather than at a desk, weigh mobile experience more heavily than the feature list suggests you should.

PDF Expert remains the strongest dedicated iPad experience specifically because Readdle built it Apple-first rather than porting a desktop app down to a smaller screen, and its Apple Pencil support with palm rejection is noticeably more polished than the competition. Xodo is the best free cross-platform option for touch input generally, working comparably well on Android and iOS rather than favoring one ecosystem. Drawboard remains the specialist choice specifically for stylus-based freehand drawing and technical review, built from the start around Surface and other pen-enabled tablets rather than finger-tap annotation.

Acrobat Reader and Foxit both ship competent but noticeably less capable mobile apps than their desktop counterparts, which matters if your workflow genuinely depends on doing serious markup work away from a keyboard rather than just glancing at a document on the go.

Large Files and Offline Access

Browser-based tools like Lumin and Smallpdf are convenient precisely because there is nothing to install, but that convenience has a real cost on large documents. A 200-page scanned PDF full of embedded images can genuinely stutter inside a browser tab in a way it never would in a native desktop app, since the browser has to hold the entire rendered document in memory alongside every other tab you have open. If your work regularly involves large scanned files, architectural drawings, or image-heavy reports, a native app, PDF Expert, Foxit, Acrobat, or Drawboard, will handle the file more smoothly than a web tool will.

Offline access follows the same pattern. Native desktop and mobile apps generally keep working without a connection once a file is downloaded, which matters if you review documents on a flight, in a basement conference room, or anywhere else with unreliable Wi-Fi. Xodo specifically supports offline annotation on mobile once a file is cached locally. Lumin, by contrast, depends on its live connection to Google Drive for both opening and saving, so it is the wrong choice for anyone who needs to keep working through a dead zone.

Which one should you actually pick?

Start free. Preview or Acrobat Reader covers highlights, notes, and signatures, the jobs that account for most PDF markup. That is the whole decision for most individuals.

Pay when a specific wall appears. Formal multi-reviewer cycles justify Acrobat Pro or Foxit. Daily annotation on an iPad justifies PDF Expert. Stylus review of technical drawings justifies Drawboard. Live co-annotation in Google Drive justifies Lumin.

The wrong move is buying Acrobat Pro because it is the famous one, then using five percent of it. Match the tool to the actual constraint you are running into, file size, platform, collaboration, or redaction, rather than defaulting to whichever name is most recognizable.

If your workflow involves generating the reports you are marking up in the first place, our roundup of the best software for writing up data analysis reports covers the tools that produce the document before it ever reaches the markup stage, and our broader look at the best PDF editing software is worth a read if annotation alone is not enough and you need to change the underlying content too.

FAQ

What is the best program to markup PDFs?

For most people, the best program to markup PDFs is one they already have: Apple Preview on Mac or Adobe Acrobat Reader on Windows, both free. If you review documents professionally, Adobe Acrobat Pro is the strongest all-rounder, with Foxit PDF Editor as the value alternative and PDF Expert as the best pick on Apple hardware.

Can I markup a PDF for free?

Yes, and without meaningful compromise for basic work. Acrobat Reader, Apple Preview, PDF24, and Xodo’s free plan all handle highlighting, comments, drawing, and signatures. You only need to pay for editing the PDF’s actual text, formal review workflows, or advanced stylus features.

What’s the difference between PDF markup and PDF editing?

Markup adds a layer on top of the document, highlights, notes, stamps, ink, without changing the original content underneath. Editing changes the content itself: rewriting text, replacing images, redacting sections. Free tools generally include full markup; editing is the feature that paid products charge for.

Will my annotations show up in other PDF apps?

Usually, yes. Highlights, sticky notes, and drawing markup follow the PDF standard, so notes made in Xodo or PDF Expert open fine in Acrobat and vice versa. The exceptions are proprietary collaboration layers, Lumin’s live comments for example, and web tools that flatten annotations into the page on export, which makes them visible but no longer editable.

What’s the best PDF markup software for iPad?

PDF Expert is the strongest overall iPad option, with fast rendering and polished Apple Pencil support. Xodo is the best free alternative, and Drawboard is worth a look if your markup is mostly freehand drawing on technical documents.

Is a black box enough to redact sensitive information from a PDF?

No, not unless the tool specifically labels it as redaction rather than annotation. A highlight or shape tool set to black only covers the text visually; the underlying text often remains selectable and extractable. Use a dedicated redaction feature, Acrobat Pro and Foxit PDF Editor both have one, whenever a document actually needs to have information removed rather than just hidden from casual view.