Best online annotation software in 2026

Last updated June 2026

Adobe Acrobat for PDFs. CleanShot X for screenshots. Frame.io for video. Google Docs comments for text documents. Four tools. Four sets of feedback. None of them connected. The annotation on the PDF doesn't know about the comment on the video. The screenshot markup doesn't link to the document it's about.

Annotation software has specialised by content type, which means most teams run multiple tools for feedback and review. Here's what works best for each format, and one tool that handles them all in the same workspace.

Quick comparison

Multi-format annotation

Fabric

Fabric is the only tool on this list that annotates across multiple content types inside the same workspace where the rest of the project lives.

What you can annotate: PDFs, markdown files, notes, JSON files, and documents with highlights and detailed comments. Any website via the browser extension with persistent annotations that survive across sessions, devices, and page reloads. Two modes: quick highlights for fast reference, detailed comments for deeper analysis. Click any comment's location tag to jump to the highlight.

What connects the annotations: Every annotation is searchable via semantic search alongside your notes, files, recordings, and saved content. The AI assistant can access, summarise, and answer questions about your annotations. Annotated files live next to the project brief, the reference images, the meeting recording where feedback was discussed, and the task to implement changes.

Share annotated content via password-protected links with per-recipient viewing analytics. Collaborative annotations with threaded replies. All private by default, sharing opt-in.

Limitations: No advanced PDF form filling or digital signatures (Adobe wins there). No frame-accurate video timecoded comments (Frame.io wins there). No measurement tools, blur, or step numbering on screenshots (CleanShot X or Snagit win there). Fabric's annotation strength is breadth and context, not depth in any single format.

Best for: Creative teams, agencies, and designers who give and receive feedback across multiple content types. Review and approval workflows where annotations need to live alongside the project. Researchers who annotate PDFs, articles, and web pages as part of a broader workflow. Teams who are tired of scattering feedback across four different tools.

PDF annotation

Adobe Acrobat Pro

Adobe Acrobat Pro is the standard for professional PDF work. Highlighting, comments, sticky notes, text markup, drawing tools, stamps, form filling, digital signatures, redaction, and measurement. The most complete PDF annotation toolkit available.

Strengths: Comprehensive markup tools. Form creation and filling. Digital signatures with legal standing. Redaction. Measurement tools for architectural and technical drawings. Shared reviews with comment syncing. AI Assistant on paid plans for summarisation and Q&A. Universal format compatibility.

Limitations: ~$23/month is expensive for annotation alone. The interface is dense. Subscription-only. Overkill for basic highlighting. Annotations live in the PDF, not connected to your broader workspace.

Best for: Legal, architectural, and professional teams who need advanced PDF markup, form filling, digital signatures, and redaction.

PDF Expert

PDF Expert is a cleaner, faster PDF annotation tool for Mac and iOS. Highlights, text, shapes, stamps, signatures, form filling. The Apple-native alternative to Acrobat.

Strengths: Clean interface. Fast on Mac and iOS. ~$80/year or $140 one-time. Smoother than Acrobat for basic-to-intermediate PDF annotation. Handles large PDFs well.

Limitations: Mac and iOS only. No Windows. No web. No AI. Fewer advanced features than Acrobat (no measurement tools, no redaction). No connection to a broader workspace.

Best for: Mac and iOS users who annotate PDFs regularly and don't need Acrobat's full feature set.

Screenshot and image annotation

CleanShot X

CleanShot X captures and annotates screenshots on Mac with 50+ markup tools. Arrows, text, blur, highlights, numbered steps, shapes. The workflow is: capture, annotate, share.

Strengths: 50+ annotation tools. Blur and pixelate. Numbered steps for tutorials. OCR text extraction. Scrolling capture. Cloud sharing. $29 one-time. The fastest screenshot annotation workflow on Mac.

Limitations: Mac only. Screenshots are standalone files, not connected to projects. No PDF, document, or web annotation. No collaboration beyond sharing links.

Best for: Mac users who annotate screenshots daily for bug reports, tutorials, and documentation. See also: best image annotation tool for more options.

Video annotation

Frame.io

Frame.io is the standard for video review and approval. Time-coded comments pinned to exact frames. Threaded replies. Version control. Side-by-side comparison. Integration with Premiere Pro, Final Cut Pro, and DaVinci Resolve.

Strengths: Frame-accurate timecoded comments. Annotations on specific video frames. Threaded conversations per timecode. Version stacking and comparison. Premiere Pro integration (comments appear as markers in the timeline). Camera to Cloud ingest. Custom-branded share links. Passphrase protection.

Limitations: Free (2 users, 2GB). Pro $15/user/month. Team $25/user/month. Video-centric: supports photos and PDFs but isn't the best tool for those. Storage caps on lower tiers. Acquired by Adobe, so pricing and feature gating are increasingly enterprise-oriented. Annotations live in Frame.io, not connected to your broader project workspace.

Best for: Video production teams, editors, and post-production houses who need frame-accurate review and approval with editorial tool integration.

Enterprise approval

Filestage

Filestage is a multi-stage approval platform. Upload images, video, PDFs, and documents. Invite reviewers. Collect pinned annotations. Route through approval stages with deadlines. Audit trail for compliance.

Strengths: Multi-reviewer approval workflows. Annotations across images, video, PDFs, and documents. Version comparison. Approval routing with role-based permissions. Audit trail. Deadline management.

Limitations: From ~$49/user/month. Enterprise pricing. Overkill for small teams or informal review. Feedback lives inside Filestage's pipeline, not alongside your broader files.

Best for: Enterprise marketing, legal, and compliance teams with formal multi-stage approval processes.

Text document annotation

Google Docs

Google Docs isn't an annotation tool, but its commenting and suggesting features are how most teams annotate text documents. Real-time comments. Suggested edits with accept/reject. Threaded conversations. Assign comments to specific people.

Strengths: Free. Real-time co-editing. Commenting and suggesting built in. Gemini AI for writing assistance. The default for collaborative text editing. Everyone has access.

Limitations: Text documents only. No PDF, image, video, or web annotation. Comments live in Google Docs, not connected to other annotation tools or your broader workspace.

Best for: Collaborative text editing. The tool everyone already uses for document feedback.

How to choose

If you annotate across multiple formats and want everything connected: Fabric. PDFs, documents, web pages, and notes in one workspace. All searchable. All AI-accessible. All connected to the project.

If you need professional PDF annotation: Adobe Acrobat Pro. The most complete toolkit. Forms, signatures, redaction, measurement.

If you need fast screenshot markup: CleanShot X. 50+ tools, blur, steps. $29 once on Mac.

If you need video review and approval: Frame.io. Frame-accurate timecoded comments. Premiere Pro integration.

If you need enterprise multi-stage approval: Filestage. Multiple reviewers, stages, audit trail.

If you annotate text documents: Google Docs. You're probably already using it.

If you're using four tools and want one: Fabric. It doesn't match the depth of any single specialist (Adobe for PDFs, Frame.io for video, CleanShot for screenshots). It matches the breadth of all of them combined, and it keeps the annotations connected to each other and to the rest of the work. For most teams, that trade-off is worth it.

The real cost of format-specific annotation

The subscription costs are visible: Acrobat $23/month, Frame.io $15-25/user/month, Filestage $49+/user/month, CleanShot $29. The hidden cost is fragmentation.

PDF feedback lives in Acrobat. Video feedback lives in Frame.io. Screenshot feedback lives in a Slack thread. Document feedback lives in Google Docs. Web feedback lives in a browser extension you forgot you installed. The design brief lives in Google Drive. The task list lives in Asana.

Nobody has a complete picture of the feedback. Nobody can search across all of it. Nobody's AI assistant understands all of it.

Fabric puts annotations alongside the project. The annotated PDF, the design brief, the meeting recording where feedback was discussed, the task to implement changes, and the published link you shared with the client. All in one workspace. All searchable. All understood by the AI.

One tool for annotation. One place for the project. One search bar for all the feedback.

FAQs

Which tool annotates the most content types? Fabric (PDFs, documents, notes, web pages). Filestage (images, video, PDFs, documents). Frame.io (video, images, PDFs). Adobe Acrobat (PDFs only). CleanShot X (screenshots only). Google Docs (text only).

Which is free? Google Docs (free). Fabric (generous free plan). Frame.io (free with 2 users, 2GB). CleanShot X ($29 one-time). PDF Expert (~$80/year). Adobe Acrobat (~$23/month). Filestage (from ~$49/user/month).

Can any tool search across annotations later? Only Fabric. Annotations are indexed by semantic search and accessible to the AI assistant. In every other tool, finding past annotations means remembering which tool and which file they were in.

Which is best for design teams? Fabric for multi-format annotation connected to design projects. Frame.io for video review. Figma for design file comments (covered in the best image annotation tool guide). Adobe Acrobat for PDF markup.

Do I really need multiple annotation tools? If you work with one content type (only PDFs, or only video), a specialist tool is the right choice. If you work across PDFs, documents, images, web pages, and video, you're choosing between managing multiple specialist tools or using Fabric for the formats it covers and a specialist for the rest. Most teams find that reducing from four annotation tools to two (Fabric plus one specialist) cuts fragmentation significantly.