25 best annotation tools for images, videos, PDFs, and more

Finding the right annotation software can mean the difference between creative projects that flow smoothly and those that blow deadlines due to endless review cycles. Whether you're marking up PDFs for legal review, annotating videos for AI training, or collaborating on marketing campaigns, the annotation tools you choose directly impact your team's productivity and output quality.

The demand for sophisticated annotation capabilities has exploded across industries. Yet many teams still struggle with fragmented workflows, scattered feedback across email threads, and the constant app-switching that kills productivity. The right annotation software eliminates these bottlenecks, centralizing feedback and accelerating your entire creative operations.

We've analyzed 25 leading annotation tools across five categories — from comprehensive creative collaboration platforms to specialized AI training solutions. This guide breaks down exactly what each tool offers, who it serves best, and how much it costs, helping you identify the perfect fit for your specific annotation needs.

What we'll cover

All-in-one annotation & collaboration software

1. Ziflow

Best for: Marketing teams and creative agencies managing high-volume creative workflows with complex approval processes

Ziflow stands out as the system of record for creative feedback, serving thousands of customers worldwide. The platform transforms how teams review, markup, and approve creative content by eliminating the patchwork of tools that typically plague creative operations. With support for over 1,200 file types, Ziflow ensures your team never hits a compatibility roadblock.

Key annotation features: 

• Frame-precise video markup with timestamp-based commenting that lets reviewers pinpoint exact moments
• Real-time collaborative commenting with color-coded markup tools including arrows, boxes, and freehand drawing
• Pixel-level version comparison for both static and video content to track changes between iterations
• Advanced text highlighting with automatic "Replace with" suggestions that streamline copy editing
• Multi-asset campaign-level reviews allowing cross-channel content evaluation in a unified environment

Pricing: Free plan includes 2GB storage and 2 users with unlimited reviewers. Standard plan at $199/month (billed annually) provides 15 users and 1TB storage. Pro plan at $329/month adds advanced features and 2TB storage. Enterprise plans offer custom pricing with unlimited workflows and white labeling.

G2 Customer Review: "I'm not exaggerating when I say it's a game-changer for me. I work for an advertising agency and Ziflow has made managing reviews and approvals from our clients so much easier," shares Harriet G., Senior Account Manager. Another user states: "Ziflow makes it easy for our team to provide clear feedback on all types of creative content. It improved project member collaboration, which helped us get projects completed faster."

2. Filestage

Best for: Marketing departments handling of visual assets with client collaboration requirements

Headquartered in Stuttgart, the platform focuses on streamlining collaboration between internal teams and external stakeholders without requiring clients to create accounts. The company has built its reputation on eliminating the friction that typically accompanies client feedback collection.

Key annotation features: 

• Visual commenting and markup directly on images, videos, and documents with contextual precision
• Version control with side-by-side comparison allowing instant visualization of changes
  
• Approval workflow automation featuring custom reviewer groups and deadline management
  
• Real-time collaboration with threaded comments keeping discussions organized
  
• Custom branding capabilities for maintaining professional appearance in client-facing reviews
  

Pricing: Basic plan starts at $199 month. Professional plan starts at $299/month and includes advanced features. Enterprise plans offer custom pricing with unlimited projects.

G2 Customer Review: "Filestage is very easy and intuitive. The review and approval process with my customers is very time-saving now, compared to sending emails back and forth. My customers are very happy with this tool and so am I," reports one verified reviewer.

3. GoVisually

Best for: Freelancers, and small to medium creative teams needing straightforward design and video collaboration

Featured in Forbes, Mashable, and Inc., GoVisually serves over 50,000 creative professionals. The platform excels at making complex review processes simple, particularly for PDF annotation and visual content collaboration. Their focus on intuitive design means teams can start collaborating immediately without extensive onboarding.

Key annotation features:

• Precise annotation tools optimized for designs, PDFs, and videos with pixel-perfect accuracy
• @mentions for instant stakeholder notification ensuring no feedback gets missed
• Version control with comprehensive project status tracking across all assets
• Birdseye project visibility providing managers with real-time oversight
• Approval workflows featuring checklist functionality for systematic review completion

Pricing: Lite plan at $16/user/month. Pro plan at $33/user/month. Enterprise plans offer custom pricing with unlimited features and SSO.

G2 Customer Review: "GoVisually has been a great tool for our designers to work more productively with the rest of our organization. It saves us so much time in the review process and is really easy for new employees coming in to learn quickly," shares a verified G2 reviewer.

4. Encord

Best for: AI and ML teams building computer vision models requiring high-precision annotation

Encord powers the world's most ambitious AI projects, with over 200 leading AI companies relying on its data development platform. The company accelerates AI model development through comprehensive data curation, labeling, and evaluation tools that handle the complexity of modern computer vision projects. Their focus on multimodal AI makes them particularly valuable for teams working across different data types.

Key annotation features: 

• AI-assisted annotation with SAM 2 integration enabling automatic segmentation with minimal input
• Multimodal annotation supporting images, videos, audio, text, and DICOM medical imaging
• Object tracking and interpolation for efficient video annotation across thousands of frames
• Custom ontologies with nested classifications supporting complex labeling hierarchies
• HITL (Human-in-the-Loop) workflows combining model-assisted labeling with human verification

Pricing: Individual plan free for early-stage startups and academic researchers. Teams and Enterprise plans feature custom pricing based on data volume and required features.

G2 Customer Review: "The Encord platform is really easy to use for annotating videos. With Encord's interpolation feature we can label videos much more efficiently than with the tools we were using previously," reports a verified user.

PDF annotation software

5. Adobe Acrobat

Best for: Enterprises and legal teams requiring comprehensive PDF editing with industry-standard compliance

Adobe Acrobat is a leader for PDF manipulation, leveraging Adobe's position as creator of the PDF format itself. The platform delivers enterprise-grade features that extend far beyond simple annotation, providing comprehensive document workflows trusted by Fortune 500 companies and government organizations worldwide.

Key annotation features:

• Comprehensive markup toolkit including highlighting, sticky notes, strikethrough, shapes, and freehand drawing
• Shared review workflows enabling real-time collaboration across distributed teams
• Advanced commenting with threaded discussions and @mentions for targeted feedback
• Form creation and electronic signatures integrated seamlessly into review processes
• Compare documents feature providing detailed version tracking and change visualization

Pricing: Acrobat Standard at $12.99/month (annual plan). Acrobat Pro at $19.99/month includes full feature set.

G2 Customer Review: "Adobe Acrobat Reader makes it really easy to open, view, and interact with PDFs without any disturbances. I especially like the ability to highlight text, add comments, and fill out forms directly within the document," shares a verified user.

6. Foxit PDF Editor

Best for: Businesses seeking Adobe alternative with advanced features at 40-60% lower cost

Foxit Software delivers fast, secure, and cost-effective PDF solutions that challenge Adobe's dominance. The company's innovation-first approach introduced the world's first PDF AI Assistant, featuring over 80 smart commands for document processing. Their strong enterprise focus and competitive pricing make them particularly attractive for cost-conscious organizations.

Key annotation features:

• ConnectedPDF technology enabling document tracking and real-time collaboration
• Comprehensive annotation toolkit with color-coded markups for reviewer differentiation
• AI Assistant with 80+ smart commands automating repetitive annotation tasks
• Advanced commenting and markup tools matching Adobe's capabilities
• OCR capabilities converting scanned documents into searchable, annotatable PDFs

Pricing: Volume discounts available for 30+ licenses with special rates for education and non-profits.

G2 Customer Review: "Foxit PDF Editor is taking care of all my PDF editing needs. It's extremely useful when putting together proposals or quotes for customers," reports a verified G2 user.

7. Xodo

Best for: Teams needing cross-platform PDF collaboration with mobile-first workflows

Developed by Apryse (formerly PDFTron), Xodo serves millions globally with comprehensive PDF solutions across all major platforms. The platform's commitment to security and cross-platform compatibility makes it ideal for teams working across different devices and operating systems, from Windows and Mac to Linux and mobile devices.

Key annotation features:

• Advanced annotation tools with full stylus support for natural handwriting
• Real-time collaboration with automatic cloud synchronization across devices
• Form filling with intelligent automatic field detection
• OCR technology transforming scanned documents into editable content
• Comprehensive markup tools including highlight, underline, strikethrough, and freehand drawing

Pricing: Web plan at $9.99/month per license (annual billing). PDF Studio at $9.99/month for desktop. Document Suite at $14.99/month includes all platforms.

8. BugSmash

Best for: Smaller creative teams and agencies needing unified feedback across multiple media types

BugSmash eliminates scattered communication by providing visual feedback and collaboration across diverse content types. The platform's unique strength lies in handling everything from PDFs to websites to audio files in a single interface, making it perfect for teams managing varied creative assets without requiring complex setup or training.

Key annotation features:

• Multi-format annotation supporting PDFs, images, videos, websites, and audio files
• Pinpoint feedback placement directly on content for precise communication
• Threaded comments and replies maintaining organized discussion histories
• No sign-up required for reviewers reducing friction in client collaboration
• Version control with comprehensive project tracking across all asset types

Pricing: Free plan includes 2 projects, 2 members, 25 guests, and 5GB storage. Starter at $7/month (billed annually) for unlimited projects with 2 members. Team at $49/month supports unlimited members and projects. Lifetime access available for $249 (Founder's special).

Customer testimonial: Fire Safe Council reports, "We needed a way to collect public comments on a complex, markup-heavy PDF. BugSmash was the only tool that truly worked."

Video annotation software

9. SuperAnnotate

Best for: AI teams and computer vision projects requiring high-quality training data with managed annotation services

SuperAnnotate ranks as the #1 Data Labeling platform on G2, serving leading organizations with end-to-end annotation capabilities for computer vision and multimodal AI. The platform's access to over 400 vetted annotation service teams sets it apart for enterprises needing scalable, high-quality data labeling with human expertise.

Key annotation features:

• Video object tracking and detection with frame-to-frame consistency
• Automated segmentation with intelligent interpolation capabilities
• Keypoint annotation optimized for pose detection and skeletal tracking
• Multi-frame object tracking with unique ID assignment maintaining object identity
• Custom annotation workflows incorporating multi-stage quality control

Pricing: Startup plan free for early-stage startups and academic researchers. Pro and Enterprise plans require custom pricing consultation based on project scope.

G2 Customer Review: "We reviewed several companies and selected SuperAnnotate due to the high quality of their data. They stand out for their data quality, attention to detail, and fantastic communication," reports a verified user.

10. Dataloop

Best for: Enterprise AI teams building production-ready applications with comprehensive data management needs

Dataloop provides an AI-ready data stack for organizations requiring end-to-end data management. With GDPR, ISO 27001, and SOC 2 Type II compliance, the platform serves enterprise customers who need robust security alongside powerful annotation capabilities. Their focus on automation and human-in-the-loop workflows accelerates AI development cycles.

Key annotation features:

• Linear interpolation and smart tracking automating video annotation workflows
• Occlusion handling for objects moving in and out of view
• Multi-speed video navigation with precise frame-by-frame control
• Cross-object relationship tracking maintaining contextual connections
• Custom workflow automation through event-driven pipelines

Pricing: Free trial available for evaluation. Enterprise pricing customized based on data volume and specific requirements.

Notable clients: Automotive companies and enterprises requiring ADAS and autonomous driving features.

11. Hive

Best for: Enterprises needing AI-powered content moderation and automated content analysis at massive scale

Founded in 2013, Hive pioneers AI content understanding with over 2 million registered contributors globally. The platform handles billions of API calls for the world's largest companies, specializing in content moderation, brand safety, and automated content analysis. Their pre-trained models enable immediate deployment without extensive setup.

Key annotation features:

• AI-powered video content moderation and classification at internet scale
• Automated object detection and tracking across video streams
• Brand logo recognition and placement analysis for sponsorship tracking
• Content understanding with sophisticated scene classification
• Multi-language content analysis supporting global deployments
  

Pricing: API-based pricing starting from $0.003 per image/video frame. Enterprise solutions feature custom pricing for high-volume usage. Managed annotation services available for specialized projects.

Platform ratings: Major social media platforms and Fortune 500 companies rely on Hive for content moderation at scale.

12. V7

Best for: AI/ML teams in healthcare, manufacturing, and automotive requiring high-precision video annotation for safety-critical applications

V7 Labs serves Fortune 500 companies including Bayer, Boston Scientific, and Continental with training data platforms designed for safety-critical AI applications. The platform's ability to handle videos up to 100K+ frames with pixel-perfect accuracy makes it essential for regulated industries where precision directly impacts safety outcomes.

Key annotation features:

• Advanced video annotation supporting up to 100K+ frames per video
• Automated annotation achieving pixel-perfect accuracy through AI assistance
• Multi-camera video synchronization for complex scene understanding
• Occlusion handling and object re-identification across frames
• Medical imaging support (DICOM) with specialized annotation tools
  

Pricing: Professional and Enterprise plans feature custom pricing based on usage requirements.

Customer testimonial: Teams report annotation speed improvements of 30%, with overall process efficiency more than doubled.

Image annotation software

13. CVAT (Computer Vision Annotation Tool)

Best for: Large-scale computer vision projects requiring diverse annotation types with enterprise-grade features

Originally developed by Intel and now maintained under the OpenCV umbrella, CVAT serves over 250,000 users globally. The open-source platform provides the most comprehensive annotation capabilities available, supporting everything from simple bounding boxes to complex 3D scene understanding. BMW Group and thousands of enterprises rely on CVAT for production AI systems.

Key annotation features:

• Widest variety of annotation tasks including object detection, tracking, segmentation, and pose estimation
• Automated annotation through integration with OpenVINO, Roboflow, and HuggingFace models
• Advanced interpolation between keyframes dramatically accelerating video annotation
• Multi-user collaboration with sophisticated task management and quality control
• Cloud storage integration supporting AWS S3, Google Cloud, and Azure
  

Pricing: Professional plans start at $33/month. Enterprise plans include SSO, SAML, and dedicated support.

Customer testimonial: Point.AI testimonial: "CVAT supports the widest variety of computer vision annotation tasks... Gone are the days where we need to design our own labeling tool."

14. RectLabel

Best for: Individual Mac users and small teams needing offline annotation for object detection projects

RectLabel brings Mac-native performance to annotation tasks, developed by Ryo Kawamura for users who prefer desktop applications over web-based tools. The integration with Apple's ecosystem, including Core ML models, makes it particularly valuable for iOS developers and Mac-based research teams.

Key annotation features:

• Segment Anything Model 2 integration enabling advanced polygon and pixel annotations
• Core ML model integration for automatic labeling leveraging Apple's machine learning
• Cubic bezier curves and oriented bounding boxes optimized for aerial imagery
• Keypoint annotation with skeleton support for pose estimation
• Built-in OCR for automatic text recognition and transcription

Pricing: Free trial available for evaluation. RectLabel offers monthly/yearly subscriptions. RectLabel Pro available as one-time purchase with pricing varying by region.

User feedback: Popular among Mac users for its native performance and integration with Apple's ecosystem.

15. Scale AI

Best for: Large enterprises needing high-volume, complex data annotation with human-AI collaboration

Scale AI, valued at $29 billion, powers AI development for OpenAI, Meta, Microsoft, and government agencies. The platform combines massive human workforce with advanced AI to deliver annotation at unprecedented scale and quality. Their managed service approach removes the complexity of annotation project management for enterprises.

Key annotation features:

• Human-in-the-loop annotation achieving massive scale with consistent quality
• Multi-modal support spanning text, audio, video, LiDAR, and point clouds
• Scale Rapid for speed-optimized projects vs Scale Studio for maximum control
• Built-in quality assurance through consensus labeling and benchmarking
• Advanced GenAI capabilities including RLHF and comprehensive model evaluation
  

Pricing: Enterprise-focused custom pricing.

Notable clients: OpenAI, Meta, Microsoft, and government agencies rely on Scale for their most critical AI training data needs.

16. Make Sense

Best for: Small projects needing quick, browser-based annotation without installation requirements

Make Sense, an open-source project by SkalskiP, prioritizes privacy and simplicity. The tool operates entirely in the browser with data never leaving the user's device, making it ideal for sensitive projects or situations where data security policies prevent cloud-based tools. Students and researchers particularly value its zero-setup approach.

Key annotation features:

• Fully browser-based operation requiring no server or installation
• Privacy-focused architecture keeping all data local to user's browser
• COCO SSD and POSE-NET model integration for AI-assisted annotation
• Support for bounding boxes, polygons, points, and lines
• TensorFlow.js powered AI assistance running directly in browser
  

Pricing: Completely free under GPLv3 license.

User feedback: Perfect for beginners and small-scale annotation needs requiring privacy.

17. LabelImg

Best for: Simple object detection tasks requiring only bounding box annotations

LabelImg, created by Tzutalin and now part of the Label Studio community, remains widely used despite no longer being actively developed. Its simplicity and focus on bounding box annotation make it a go-to tool for educational purposes and basic object detection projects where advanced features would add unnecessary complexity.

Key annotation features:

• Graphical bounding box annotation with streamlined interface
• Pascal VOC, YOLO, and CreateML export format support
• Simple Python/Qt interface ensuring cross-platform compatibility
• Extensive keyboard shortcuts maximizing annotation speed
• Lightweight installation with minimal dependencies

Pricing: Free and open-source.

User base: Widely used in academic settings and for learning computer vision basics.

18. Roboflow

Best for: Developer-focused teams needing integrated pipeline from annotation through model deployment

Roboflow serves over 250,000 developers with an end-to-end computer vision platform. The company's focus on developer experience shows in their comprehensive documentation, active community, and Universe model hub. BNSF Railway and Pella Corporation trust Roboflow for production computer vision applications.

Key annotation features:

• Label assist leveraging AI models for automatic annotation
• Dataset preprocessing with 50+ augmentation options
• One-click model training and deployment streamlining workflows
• Credit-based usage system providing flexibility across features
• Strong community ecosystem through Universe model hub
  

Pricing: Free Public plan available with limitations. Basic plan at $49/month. Growth and Enterprise plans feature custom pricing. 

Customer testimonial: BNSF Railway reports: "Roboflow is helping us immediately realize value from state-of-the-art computer vision technology."

19. VGG Image Annotator (VIA)

Best for: Academic research and simple annotation tasks requiring offline capability

Developed by the Visual Geometry Group at Oxford University, VIA delivers lightweight annotation capabilities in a single HTML file under 500KB. The academic backing and minimal requirements make it perfect for research projects, particularly in educational settings where simplicity and offline functionality are priorities.

Key annotation features:

• Lightweight design enabling complete offline operation
• Support for rectangles, circles, ellipses, polygons, and points
• Image, audio, and video annotation in unified interface
• Attribute annotation for adding metadata to objects
• Browser-based operation requiring no installation

Pricing: Free under BSD-2 clause license.

User base: Popular in academic and research settings.

Data annotation software

20. Labellerr

Best for: Teams needing fast, automated annotation across multiple data types with high accuracy

Labellerr accelerates annotation workflows through AI-powered automation, claiming 60% time savings while maintaining 99.8% accuracy. The platform's strength lies in balancing automation with human oversight, ensuring quality while maximizing efficiency across diverse data types from images to PDFs.

Key annotation features: 

• AI-powered automation reducing manual annotation time by 60%
• Multi-modal support covering images, videos, text, PDFs, and audio
• Active learning and model-assisted labeling improving over time
• Human-in-the-loop workflows ensuring quality assurance
• Smart quality assurance achieving 99.8% accuracy claims
  

Pricing: Researcher Plan free for students and researchers with 2,500 credits. Pro Plan at $499/month includes 50,000 credits and 10 seats. Enterprise plans offer custom pricing.

G2 Rating: 4.8/5 rating with users praising speed improvements and accuracy.

21. Labelbox

Best for: Enterprise AI teams needing comprehensive data-centric AI platform with advanced collaboration

Founded in 2017 and backed by SoftBank and Andreessen Horowitz, Labelbox serves Fortune 500 clients including Walmart, P&G, and Adobe. The platform takes a data-centric approach to AI development, recognizing that model performance depends more on data quality than algorithm selection.

Key annotation features:

• Model-assisted labeling with AI critics evaluating annotation quality
• Multi-modal evaluation supporting diverse data types
• Collaborative workflows with granular role-based access control
• Quality control through consensus labeling and benchmarking
• Deep integration with major cloud platforms
  

Pricing: Enterprise plans feature custom pricing with advanced capabilities.

G2 Rating: 4.5/5 rating with users praising collaboration features and API management.

22. Supervisely

Best for: Computer vision teams needing end-to-end platform from annotation through deployment

Founded in 2017, Supervisely manages over 220 million images and 1 billion labels across its community. BMW Group uses the platform for manufacturing quality inspection, demonstrating its enterprise readiness. The comprehensive approach eliminates tool fragmentation by providing everything from annotation to model deployment.

Key annotation features:

• Complete computer vision pipeline including integrated model training
• Support for all data types including images, videos, 3D point clouds, and DICOM
• 200+ pre-built applications and models accelerating development
• Advanced team collaboration with sophisticated project management
• Extensive SDK/API enabling custom tool development

Pricing: Free for non-commercial use without credit card requirement. Pro and Enterprise plans available for businesses. On-premise Enterprise Edition offered for maximum control.

Customer base: BMW Group and 12,000+ businesses rely on the platform.

23. Amazon SageMaker Ground Truth

Best for: AWS ecosystem users needing integrated data labeling with machine learning workflows

Amazon SageMaker Ground Truth reduces data labeling costs up to 70% through active learning and automation. The managed service integrates seamlessly with the broader AWS ecosystem, making it the natural choice for teams already using AWS for their infrastructure and machine learning pipelines.

Key annotation features:

• Integration with Amazon Mechanical Turk and private workforce options
• Active learning reducing labeling requirements through smart sampling
• Built-in workflows for common labeling tasks
• Automatic labeling using ML models for applicable data
• Seamless integration with complete SageMaker ML pipeline
  

Pricing: Pay-as-you-go starting at $0.08/month. Free tier includes 250 hours of various instance types and 25 hours of Data Wrangler. Charges apply for compute instances, storage, and human annotation tasks.

User feedback: Best suited for teams already invested in AWS infrastructure.

24. DataTurks

Best for: Teams needing simple, fast setup for basic annotation with good collaboration

Founded in 2018 by ex-Flipkart executives and acquired by Walmart Labs in 2019, DataTurks focuses on simplicity and speed. The platform claims 5x faster tagging speed compared to traditional methods, achieved through thoughtful interface design and keyboard shortcuts. An open-source version ensures longevity and flexibility.

Key annotation features: 

• Pre-built support for image, NLP, and video annotation tasks
• Team collaboration with straightforward invite system
• API access enabling workflow integration
• Simple interface with extensive keyboard shortcuts
• 5x faster tagging speed through optimized workflows

Pricing: Open-source self-hosted option provides free alternative.

User feedback: Teams working with sensitive data appreciate the secure platform and self-hosted option.

25. Appen

Best for: Large enterprises needing multilingual data annotation with global managed services

With 27+ years of experience and over 1 million contractors across 170+ countries, Appen delivers data annotation at global scale. The company's support for 235+ languages and dialects makes them indispensable for international AI projects requiring diverse linguistic and cultural perspectives.

Key annotation features:

• Massive global workforce of 1M+ vetted contributors
• 235+ languages and dialects supporting truly global AI
• Custom data sourcing and collection capabilities
• Model evaluation and human preference scoring for LLMs
• AI Data Platform (ADAP) with integrated automation tools
  

Pricing: Custom project-based pricing with no public rates.

Customer base: Leading technology companies rely on Appen for large-scale annotation projects.

Choosing the right annotation software for your team

The annotation software landscape offers solutions for every need and budget, from free open-source tools to enterprise platforms managing billions of annotations. Your choice depends on several critical factors: the types of content you work with, your team size and technical expertise, integration requirements with existing workflows, and of course, budget constraints.

For creative teams and marketing departments managing diverse content types with complex approval workflows, Ziflow provides the most value. The ability to handle 1,200+ file types while maintaining enterprise-grade security and compliance makes these solutions ideal for organizations where creative operations directly impact business outcomes. The investment in proper annotation software pays dividends through faster project completion, fewer revision cycles, and elimination of costly errors that slip through fragmented review processes.

Ready to transform your creative operations? Experience how Ziflow can streamline your entire review and approval process with a personalized demo tailored to your specific workflow needs. Or start immediately with our free plan and discover why thousands of creative teams trust Ziflow to free the flow of great content.