List of the Top AI Vision Models for Vellum in 2026

Claude Fable 5.1 is an advanced general-purpose AI model from Anthropic focused on coding, scientific research, knowledge work, business processes, and long-horizon agentic reasoning. It is the generally available counterpart to Claude Mythos 5.1, which uses the same underlying model but is offered with different safeguards for vetted cybersecurity and life sciences users. Compared with Claude Fable 5, Fable 5.1 shows stronger performance across agentic coding, research, computer use, multidisciplinary reasoning, business workflow automation, and other complex benchmarks. The model is designed to remain effective during long-running tasks that involve planning, tool use, repeated verification, code modification, research, and multi-step decision making. In software engineering scenarios, it can investigate difficult bugs, trace problems across large codebases, perform code review, and work through complex implementation tasks with less supervision. Anthropic also positions Fable 5.1 as a stronger research model, with demonstrated capabilities in scientific analysis, computational modeling, and other technically demanding workflows. Improvements to cache-read pricing reduce the cost of reusing previously processed context, making the model more economical for workflows that involve long conversations, large codebases, or repeated tool calls. Fable 5.1 introduces updated enterprise privacy and security options, including Enterprise Frontier Safeguards and zero-data-retention access for eligible customers during the rollout period. Its cybersecurity protections are designed to permit more benign defensive security work, including vulnerability discovery, while continuing to restrict higher-risk activities such as exploit development and certain penetration-testing tasks. The model is available through Claude.ai, Claude Code, Claude Cowork, the Claude API, Amazon Web Services, Google Cloud, and Microsoft Azure under the claude-fable-5-1 model identifier for API users.

Claude Mythos 5 is Anthropic’s restricted-access Mythos-class AI model built for trusted organizations that require the highest level of Claude capability. The model shares the same underlying architecture as Claude Fable 5, but is offered with certain safeguards removed for approved use cases and vetted users. Claude Mythos 5 is designed for advanced cybersecurity, software engineering, scientific discovery, long-context reasoning, and autonomous research workflows. It is initially deployed through Project Glasswing for cyberdefenders and critical infrastructure providers. The model is intended to help security teams analyze complex systems, support defensive cybersecurity work, and protect important software environments. Claude Mythos 5 also demonstrates major potential in life sciences, where it can assist with protein design, binding-site selection, bioinformatics workflows, and research hypothesis generation. Anthropic reports that the model can carry out extended technical tasks, recover from failures, and operate with a high degree of autonomy. Its capabilities in genomics include assembling large-scale single-cell datasets and designing custom machine learning approaches for biological research. Because these capabilities may be dual-use, Anthropic limits access through trusted programs and applies a 30-day retention policy for Mythos-class traffic. The model is priced at $10 per million input tokens and $50 per million output tokens. Claude Mythos 5 helps vetted organizations apply frontier AI to critical defense, infrastructure, and scientific problems while maintaining controlled access and oversight.

Claude Opus 4.7 represents a major step forward in AI model development, focusing on advanced reasoning, coding, and enterprise-level task execution. It improves significantly over Opus 4.6 by delivering stronger performance on complex and high-effort software engineering challenges. The model is particularly effective at managing long-running processes, maintaining consistency, and producing reliable outputs over time. Its enhanced instruction-following capabilities ensure that it interprets prompts more literally and executes tasks with greater precision. Opus 4.7 also features advanced self-checking mechanisms, enabling it to validate its own responses before completion. A major highlight is its improved multimodal support, allowing it to process high-resolution images and extract fine visual details. This capability is especially useful for tasks like analyzing technical screenshots, interpreting diagrams, and supporting computer-based workflows. The model produces high-quality professional outputs, including refined documents, presentations, and UI designs that meet business standards. It also demonstrates strong performance across industries such as finance, legal services, and data analysis. Enhanced memory capabilities allow it to retain important context across sessions, making it more efficient for ongoing projects. Opus 4.7 includes safety and alignment improvements, with systems in place to detect and block potentially harmful or restricted use cases. It introduces new controls for balancing reasoning depth and response speed, giving users flexibility based on task complexity. Widely accessible through APIs and major cloud platforms, Opus 4.7 is designed to support scalable, high-performance AI applications for modern enterprises.

Claude Sonnet 4.6 is the latest evolution in Anthropic’s Sonnet model family, offering major advancements in coding, reasoning, computer interaction, and knowledge-intensive workflows. Designed as a full upgrade rather than an incremental update, it improves consistency, instruction following, and multi-step task completion across a broad range of professional applications. The model introduces a 1 million token context window in beta, enabling users to analyze entire codebases, long contracts, research archives, or complex planning documents in one cohesive session. Developers with early access reported a strong preference for Sonnet 4.6 over Sonnet 4.5 and even favored it over Opus 4.5 in many real-world coding tasks. Users highlighted its reduced overengineering tendencies, improved follow-through, and lower incidence of hallucinations during extended sessions. A major enhancement is its improved computer-use capability, allowing it to operate traditional software environments by interacting with graphical interfaces much like a human user. On benchmarks such as OSWorld, Sonnet models have shown steady gains in handling browser navigation, spreadsheets, and development tools. The model also demonstrates strategic reasoning improvements in long-horizon simulations, such as Vending-Bench Arena, where it optimizes early investments before pivoting toward profitability. On the Claude Developer Platform, Sonnet 4.6 supports adaptive thinking, extended thinking, and context compaction to maximize usable context length. API enhancements now include automated search filtering, code execution, memory, and advanced tool use capabilities for higher-quality outputs. Pricing remains consistent with Sonnet 4.5, making Opus-level performance more accessible to a broader user base. Available across Claude.ai, Cowork, Claude Code, the API, and major cloud platforms, Sonnet 4.6 becomes the new default model for Free and Pro users.