5 PDF proofing tools to improve collaboration and feedback

PDF proofing is a vital step for any team that reviews and processes documents. It helps them make sure that every mark, comment, and change gets captured before final approval.   

Using the right tools can help shorten the time for review cycles, prevent revision chaos, and keep everyone on the same page. Modern software solutions help gather efficient feedback from your team and stakeholders, all while keeping your PDF documents organized and up to date.

In this guide, we’ll dive further into what PDF proofing is and what features you should look for when choosing proofing software. We’ll then dig into five of the best online proofing tools available.

Disclosure: Ziflow is our product and is included in this comparison. We've applied the same evaluation criteria to all tools listed and included honest assessments of each, including our own. We encourage you to verify our findings using independent review platforms like G2 and Gartner Peer Insights.

What we'll cover

What is PDF proofing?

PDF proofing is the process of reviewing, annotating, and providing feedback on PDF documents before final approval. It ensures accuracy, consistency, and compliance with any brand and industry standards. Teams in all departments — including design, publishing, legal, and marketing teams — rely on this process to catch errors, layout issues, and potential compliance violations.

In practice, PDF proofing is much more than reading a document. It means actively making notes, highlights, and corrections that guide revisions.

This process is typically done in a centralized location, like PDF proofing software, which allows teams and stakeholders to work collaboratively in real time. It’s an effective approach that helps reduce miscommunications and endless email threads with multiple attachments and versions of the same document.

Key features of PDF proofing tools

PDF proofing tools are designed to simplify and streamline the proofing process, reducing back-and-forth emails to ensure every comment gets attention. They do this through a few key features:

• Annotation and markup tools: Quickly add notes, highlights, and shapes to pinpoint changes.
• Version control and comparison: Track changes between PDF versions to see updates, and if needed, revert to previous versions.
• Approval workflows: Set up multi-stage approval workflows with clear checkpoints or simple one-step approvals.
• Comment management: Organize and gather feedback in one place to ensure no comments fall through the cracks.
• Integration with other creative and project management tools: Connect with design and project management systems to minimize platform switching and boost productivity.
• Mobile and cloud accessibility: Review and annotate documents from any device — essential for remote teams and people on the go.
• Security and permission control: Protect sensitive information with customizable access rules so users can only view and edit documents they should have access to.
• Automated notifications and reminders: Get reminders to keep the review process on track by prompting action when you need feedback for approaching deadlines.
• Measurement and design tools: Verify that design elements meet required specifications, which is especially important for creative projects that need precise alignment and spacing.
• Audit trails and compliance tracking: Maintain detailed records of every change to stay compliant with industry regulations and maintain clear audit trails.

The top 5 PDF proofing tools

The right online proofing software for PDFs depends on your team’s needs and workflow. Below are some of the top solutions that improve collaboration and simplify feedback processes.

Our team evaluated PDF proofing solutions across five dimensions: annotation and markup depth, workflow automation and approval capabilities, version control and comparison features, integration ecosystem, and value for price. We considered third-party review data from G2 and Gartner Peer Insights, conducted hands-on testing of each platform's PDF proofing features, and consulted user feedback from industry communities. Ziflow is our own product and is included in this comparison — we've noted this throughout and applied the same evaluation criteria to our platform.

1. Ziflow

Ziflow's G2 score: 4.5/5 with 935 reviews

Ziflow is an online proofing platform built for creative teams reviewing PDFs alongside other asset types (video, web, images). It centralizes feedback and routes approvals through structured workflows.

Top features:

• Side-by-side version comparison so reviewers can see exactly what changed between rounds.
• Markup tools designed for PDFs, including text annotations, drawing, and threaded comments tied to specific page regions.
• Automated approval routing with sequential or parallel stages, deadlines, and reminders.
• Integrations with Adobe Creative Cloud, Figma, Slack, Microsoft Teams, and major DAMs and project management tools.
• Compliance-ready audit trails with electronic signatures, suitable for regulated industries (pharma, finance, agencies handling client sign-off).

Limitations: Ziflow's pricing sits at the higher end of this list, which can be a stretch for solo freelancers or very small teams. The breadth of workflow configuration also means there's a learning curve for first-time admins setting up automations and stages.

Ziflow is best for mid-market and enterprise creative teams that need structured approval workflows and audit trails across more than just PDFs.

2. Markup.io

Markup.io's G2 score: 4.7/5 with 25 reviews 

Markup.io is a streamlined solution for teams that need efficient PDF proofing without extra complexity. Its focus is on simplicity, which makes it ideal for quick feedback cycles.

Top features:

• Clear version changes to monitor feedback between reviews
• Simple approval processes to keep reviews moving forward
• Browser-based interface to access the tool without installation
• Chrome extension to mark up documents straight from a live website
• Guest user access so external stakeholders can collaborate without an account

Markup.io is best for teams looking for speed and ease of use. Its clean design makes it accessible to users at every level of technical experience.

3. Proofhub

ProofHub's G2 score: 4.6/5 with 117 reviews 

Proofhub blends project management with PDF proofing capabilities. It’s well-suited for teams that need an all-in-one solution to manage creative proofing with other project management tasks.

Top features:

• Task management with deadline tracking to keep projects moving and teams accountable
• Integrated communication to reduce the need for external messaging
• Project templates to streamline repetitive processes
• White labeling to personalize Proofhub with your brand’s look and feel

Proofhub is ideal for teams that need a robust project management solution alongside their creative review tool. The user-friendly interface helps bridge the gap between design and execution.

4. GoProof

GoProof's score: 4.3/5 with 15reviews 

GoProof speeds up the review process by focusing on instantaneous communication. The interface works well for teams collaborating in real time, helping them work together easily and efficiently.

Top features:

• Real-time updates to keep everyone up to date with the latest version
• Mobile-friendly design that makes projects accessible on any device
• Advanced permissions for secure file sharing internally and externally
• Insights dashboard to set benchmarks and continuously improve your workflows
• Search feature to quickly find information anywhere on the platform

GoProof is excellent for teams that value speed and collaboration. Real-time collaboration capabilities ensure feedback is shared instantly so projects can stay on schedule.

5. ReviewStudio

ReviewStudio's G2 score: 4.7/5 with 155 reviews

ReviewStudio is tailored for teams that need detailed design and creative proofing. It offers tools for precise and comprehensive reviews, as well as features that help you keep feedback organized, clear, and actionable.

Top features:

• Compare mode to look at different PDF versions side-by-side
• Create tasks out of feedback to streamline management
• Customizable review stages to set specific review points and ensure thorough checks at every phase
• Precise annotations that include predefined shapes, freehand, and regular comments
• Organize feedback with labels to help sort and search more easily

ReviewStudio stands out in its attention to detail. It’s perfect for teams with tight review processes that need to thoroughly document every change.

How to Choose the Right PDF Proofing Tool

The right tool depends less on feature checklists and more on how your team actually works. A few questions to anchor the decision:

• What are you actually reviewing? If PDFs are 90% of your workload, a focused tool like PDF Reviewer Pro or Markup.io may be the fastest path. If you're reviewing PDFs alongside video, web, and image assets, a broader proofing platform (Ziflow, Filestage) will save you from juggling multiple tools.
• How structured does the approval need to be? Solo reviewers and small teams often do fine with lightweight markup tools. Teams with multi-stage sign-off, compliance requirements, or external client approvals will get more out of platforms with routing, deadlines, and audit trails.
• Who else needs to be in the loop? If stakeholders live in Slack, Teams, or a specific PM tool, prioritize integrations over standalone features. The best tool is the one your reviewers will actually open.
• What's your budget reality? Free and low-cost tools (Markup.io, PDF Reviewer Pro's free tier) cover a lot of ground for small teams. Mid-market and enterprise pricing is justified mainly by workflow automation, compliance, and admin controls.

Use the criteria above to shortlist two or three tools that fit your situation, then trial them on a real project before committing. Most of these platforms offer free trials, and a week of actual use will tell you more than any feature list.