makr.io

makr.io is a free platform offering browser-based developer tools and reusable Claude Code skills for building and shipping web applications. Created by developer René DeAnda, it provides privacy-first utilities that run entirely in the browser alongside copiable SKILL.md files that integrate directly into development workflows.

Key Features

• 85+ free browser tools covering code formatting and conversion, JSON manipulation (formatting, validation, diff, merge, schema generation, CSV conversion), PDF editing (merge, split, compress, watermark, extract text, convert to images), color design (picker, palette generator, gradient generator, contrast checker, brand color library), HTML and CSS processing (formatting, minification, validation, Markdown conversion, OG image generation), email preview and validation (DMARC checking, header analysis), and security header scanning. All tools run client-side with zero data uploaded to servers.
• 100+ Claude Code skills organized into eight categories: engineering (code review, testing, debugging, refactoring, migration, monorepo setup), backend and APIs (API design, database schema, auth, payments, file uploads, search, real-time features), mobile (React Native, SwiftUI, Kotlin, Electron, push notifications, app store submission), DevOps (CI/CD, Docker, monitoring, security audit, internationalization, load testing), product (specs, MVP scoping, roadmaps, prioritization, competitive analysis, user research), design (accessibility, design system components, color and typography systems, forms, data visualization, animations), marketing and growth (landing page copy, SEO, analytics, social media, blog posts, newsletters), and AI and automation (AI features, chatbots, RAG, prompt engineering, voice AI, content pipelines). Each skill is a ready-to-use SKILL.md file that can be copied into any project.
• An interactive Ship Your First App guide walks beginners through the entire process of creating a web application: setting up developer accounts (GitHub, Vercel, Cloudflare, AI assistant), generating an app idea with AI, creating a GitHub repository, building with AI coding tools (Claude Code, Lovable, Cursor, Codex, or GitHub Copilot), pushing code to GitHub, deploying to Vercel, configuring a custom domain via Cloudflare, and sharing the launch publicly.

Use Cases

• Developers needing quick browser utilities for formatting, converting, or testing code, JSON, HTML, CSS, or PDFs without installing any local software or signing up for an account.
• Claude Code users who want pre-written, production-quality skill files for common development tasks such as code review, security auditing, SEO optimization, accessibility auditing, deployment, and performance testing.
• Beginners learning to ship their first web application through the guided step-by-step workflow covering the complete end-to-end pipeline from idea generation to a live, publicly accessible website with a custom domain.
• Product managers and designers who need structured Claude Code skills tailored to their workflows, including product specs, user research plans, competitive analysis, and sprint retrospectives.

Integrations

• Supports Claude Code, Lovable, Cursor, Codex (OpenAI), and GitHub Copilot as AI coding assistants for building applications.
• Integrates with GitHub for version control and code hosting, Vercel for zero-configuration deployment and hosting, and Cloudflare for domain registration and DNS management.

Pricing

• All browser-based tools are completely free to use with no sign-up or account required.
• Claude Code skills are free to copy and use. Using the skills with Claude requires a Claude Pro subscription or equivalent plan ($20/month).
• The Ship Your First App guide recommends approximately $20/month for an AI assistant subscription and around $15/year for a custom domain through Cloudflare at-cost pricing.

Privacy and Security

• All browser tools process data entirely on the client side. No code, files, or personal data are transmitted to or stored on external servers.
• The platform does not require account creation, sign-up, or data collection for accessing any of the browser tools.