Frame0

Frame0 is a desktop application for low-fidelity wireframes, interactive prototypes and technical diagrams. It is most suitable for designers, product teams and developers who prefer sketch-style work saved as portable files on Linux, macOS or Windows. The free edition is unusually unrestricted for ongoing wireframing, while paid licensing is aimed at users who need more device coverage.

Overview

Frame0 brings interface sketching, clickable flows and several diagram types into one desktop tool. Its component library covers desktop, mobile, smartwatch and web interfaces, and adjustable component states help represent variations without drawing every state from scratch. The deliberately rough visual language is useful for discussing structure and behavior early; teams seeking polished visual design should look elsewhere.

Documents are stored as individual files. The maker’s workflow supports syncing those files through iCloud, Dropbox, Google Drive or Microsoft OneDrive, which suits organisations that already manage project files this way. It is not a built-in collaborative workspace, so teams must establish their own file-sharing and versioning process. MKLabs says it does not process sensitive personal information and describes organisational and technical safeguards, while acknowledging that complete security cannot be guaranteed.

Key features

Shapes can connect to other pages, external URLs and navigation actions. Presentation mode turns those links into a demonstrable flow, and export to one HTML or PDF file makes it practical to send a prototype beyond the app. PDF export can omit characters that the selected font does not contain, so font choice matters when documents include unusual glyphs.

More than 1,500 sketch-style icons based on Lucide cover common interface needs without requiring a separate icon source. Diagramming extends the app beyond screens: flowcharts, entity-relationship diagrams, UML use-case diagrams and UML class diagrams are supported. That combination is valuable when a project needs both interface concepts and a map of the underlying system.

The experimental AI Agent can use an API key from OpenAI, Anthropic, Google Gemini or xAI Grok. Those providers bill their own usage separately, so AI costs sit outside Frame0’s licence. An MCP server also connects the desktop app to MCP-capable AI services such as Claude Desktop and Cursor, giving technically inclined teams an integration route without making AI a requirement for ordinary wireframing.

Pricing

The Free plan costs 0.00 USD and has no time limit or size limit. It includes all non-premium features, built-in shapes and all 1,500 icons, making it a credible long-term option for individuals who can work within the free feature set rather than merely a trial.

Solo costs $99 a month, VAT excluded, for one device. Duo costs $159 a month, VAT excluded, for two devices. Team costs $79 a month, VAT excluded, for three or more devices. The lower monthly price of Team only makes sense when the licence covers at least three devices; Solo is the straightforward choice for a single machine, while Duo fits a two-device setup. A purchased licence is perpetual, although moving to a major new version may require another payment. Refunds are available within 14 days of purchase.

Platforms

Frame0 runs on Linux, macOS and Windows. The download requirements are macOS 15 or later, Windows 10 or later, and Ubuntu 22.04 or Fedora 40 or later on Linux. It is therefore a desktop-first choice rather than a browser tool, and older operating-system installations may not qualify.

Who it's for

Choose Frame0 for early product definition, interface architecture, clickable user-flow reviews and teams that also need UML or data diagrams. Its file-based model works well for individuals and organisations already using a synchronised drive. It is less suitable for groups that require an integrated online workspace, polished high-fidelity output or predictable cross-version licensing without upgrade charges.

Pros and cons

Pros

• Generous free edition: no expiry or document-size cap, with all built-in shapes and 1,500 icons.
• Broad sketching scope: one library covers four interface contexts, while diagram tools handle flowcharts, ER diagrams and UML.
• Portable sharing: single-file HTML and PDF exports make demonstrations easy to distribute.
• Desktop AI connectivity: provider choice and MCP support suit teams already using external AI services.

Cons

• File coordination is yours to manage: syncing depends on services such as Dropbox or OneDrive rather than a native shared workspace.
• Paid plans are device-based: Solo and Duo cover only one and two devices, and Team requires at least three.
• Major upgrades may cost extra: perpetual ownership does not guarantee free future major versions.
• Low fidelity by design: the sketch aesthetic is a poor fit for final visual-design presentation.

Alternatives

Fluid UI is a better fit when Android, iOS or browser access matters alongside desktop platforms, and it offers both a free plan and free trial.

Justinmind suits teams wanting a free editor plan with one project, unlimited screens and viewers, plus UI design and wireframing across web and desktop ecosystems.

Mockplus is preferable when a free workspace for up to 10 users and 10 active projects is more important than Frame0’s local-file model.

Quickmock is a free, open-source option distributed under an MIT licence.

MockFlow offers a browser and desktop-oriented alternative with a free Basic plan for one editor and five reviewers.

Mokkup.ai is a web-only choice with a free tier limited to one editable project and three screens per project.

Pencil Project is a completely free desktop alternative for Linux, macOS and Windows.

Visily is aimed at browser users who want AI-assisted design with monthly credit-based plans.

Verdict

Frame0 is a strong choice for individuals and teams who want an unlimited free starting point, sketch-style components, clickable prototypes and system diagrams in one cross-platform desktop app. Its main reason to choose it is the breadth of practical early-stage work available without a subscription. Look elsewhere if your priority is built-in online collaboration, high-fidelity design or licence terms that guarantee every major upgrade.