Show HN Apr 2026
"Show HN" is where developers showcase their own products and projects on HackerNews. We pick the top-scoring launches every day.
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A new benchmark for testing LLMs for deterministic outputs
Show HN A comprehensive benchmark suite for evaluating how reliably LLMs produce structured, consistent outputs across different scenarios.
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My retired dad and I made a daily, somewhat difficult, quiz
Show HN A daily challenging quiz created by a father-son duo to test your knowledge
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Pi-hosts – Give the Pi coding agent access to your servers
Show HN Tool that enables Pi AI coding agent to securely connect and manage your servers remotely.
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Adblock-rust Manager – Firefox extension to enable the Brave ad blocker
Show HN Firefox extension that integrates Brave's powerful Rust-based ad blocking engine into Firefox browser for enhanced ad protection.
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Auto-Architecture: Karpathy's Loop, pointed at a CPU
Show HN Automated CPU architecture optimization using Karpathy's learning loop methodology
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Rocky – Rust SQL engine with branches, replay, column lineage
Show HN A Rust-based SQL engine that supports git-like branching, query replay, and data lineage tracking.
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Rip.so – a graveyard for dead internet things
Show HN A digital memorial site that chronicles and preserves defunct websites, apps, and online services that have shut down.
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TiGrIS, a tiling compiler that fits ML models onto embedded devices
Show HN A compiler that optimizes ML models for embedded devices through memory tiling techniques.
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49Agents – 2D Canvas IDE for Orchestrating Agents, Repos, Issues
Show HN A visual canvas-based IDE that helps orchestrate AI agents, repositories, and issues in a 2D workspace environment.
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GeoTraceroute – Traceroutes on a 3D globe and submarine cables
Show HN Visualize network traceroutes on an interactive 3D globe with submarine cable routes.
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I wrote a DOOM clone in my own programming language
Show HN Developer creates a DOOM-style game using their custom programming language Spectre
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I mapped the latest UK fuel prices by county
Show HN Interactive map showing real-time fuel prices across UK counties for easy comparison
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Open Bias – proxy that enforces agent behavior at runtime
Show HN A runtime proxy system that monitors and enforces behavioral constraints on AI agents to prevent unwanted actions.
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PrePrompt – rewrites vague prompts before they reach the LLM
Show HN A tool that automatically enhances unclear prompts with context and specificity before sending them to AI models.
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Drive any macOS app in the background without stealing the cursor
Show HN Control macOS apps in the background without interrupting your current cursor focus
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Waiting for LLMs Suck – Give your user a game
Show HN Turn boring LLM loading screens into engaging mini-games to keep users entertained while waiting for AI responses.
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Unusual Wikipedia
Show HN A curated collection of the strangest and most bizarre Wikipedia articles ever written.
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Live Sun and Moon Dashboard with NASA Footage
Show HN Real-time dashboard displaying live solar and lunar imagery using NASA's satellite data and footage.
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I built a dual crossword puzzle where two crosswords share one grid
Show HN A unique crossword puzzle format where two separate puzzles overlay on a single grid.
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AgentSwift – Open-source iOS builder agent
Show HN An open-source AI agent that automatically builds iOS applications using Swift code generation and development workflows.
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I remade my blog into a Windows 3.1 environment
Show HN A creative blog redesign that perfectly recreates the nostalgic Windows 3.1 interface
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OSS Agent I built topped the TerminalBench on Gemini-3-flash-preview
Show HN Open-source AI agent that achieved top performance on TerminalBench using Gemini-3-flash-preview
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Utilyze – an open source GPU monitoring tool more accurate than nvtop
Show HN Open source GPU monitoring tool that provides more accurate performance metrics than nvtop
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A terminal spreadsheet editor with Vim keybindings
Show HN A lightweight terminal-based spreadsheet editor featuring Vim-style navigation and editing commands.
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AgentSwarms – free hands-on playground to learn agentic AI, no setup
Show HN Interactive playground for learning AI agent development without installation
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Startup Equity Adventure Game
Show HN An interactive game that teaches startup equity and stock options through engaging scenarios and decision-making challenges.
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Tiao, A two-player turn-based board game
Show HN A strategic two-player board game featuring turn-based gameplay mechanics
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The Unix Magic poster, annotated (updated)
Show HN An annotated poster explaining Unix command-line magic with detailed examples and explanations
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AI memory with biological decay (52% recall)
Show HN An AI memory system that mimics human forgetting patterns with 52% recall rate
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Free textbook on engineering thermodynamics
Show HN A comprehensive free online textbook covering fundamental principles of thermodynamics for engineering students and professionals.
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Auge Vision from Your Terminal
Show HN AI-powered computer vision tool that processes images and videos directly from your command line interface.
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A free ESG stock screener that publishes its losses and methodology
Show HN A transparent ESG stock screener that openly shares its investment losses and screening methodology for free.
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I remade my blog into a Windows 3.1 environment
Show HN A creative personal blog designed to look and feel like the classic Windows 3.1 interface
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Browse GitHub repos in Emacs without cloning
Show HN An Emacs package that lets you explore GitHub repositories directly in your editor without downloading them locally.
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Turning a Gaussian Splat into a videogame
Show HN Tutorial on converting Gaussian splatting 3D reconstruction into an interactive game using PlayCanvas engine.
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Kloak, A secret manager that keeps K8s workload away from secrets
Show HN A Kubernetes secret manager that isolates workloads from sensitive data for enhanced security.
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HNswered – watches for replies to your Hacker News posts and comments
Show HN A tool that monitors and notifies you when someone replies to your Hacker News posts or comments.
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A Karpathy-style LLM wiki your agents maintain (Markdown and Git)
Show HN An AI agent-maintained wiki system using Markdown and Git for LLM knowledge management.
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I've built a nice home server OS
Show HN A lightweight, user-friendly operating system designed specifically for home servers and personal cloud setups.
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Browser Harness – Gives LLM freedom to complete any browser task
Show HN A tool that enables large language models to autonomously control browsers and complete web tasks.
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Atomic – Local-first, AI-augmented personal knowledge base
Show HN A local-first personal knowledge management app enhanced with AI capabilities for organizing and connecting your ideas.
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leaf – a terminal Markdown previewer with a GUI-like experience
Show HN A terminal-based Markdown previewer that provides a graphical user interface experience in the command line.
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How LLMs Work – Interactive visual guide based on Karpathy's lecture
Show HN Interactive visual guide explaining how large language models work, based on Andrej Karpathy's lectures
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Gova – The declarative GUI framework for Go
Show HN A declarative GUI framework for Go that enables building user interfaces with a modern, React-like approach.
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Run coding agents in microVM sandboxes instead of your host machine
Show HN A tool that runs AI coding agents safely in isolated microVM environments rather than directly on your computer.
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Tolaria – open-source macOS app to manage Markdown knowledge bases
Show HN Open-source macOS application for organizing and managing Markdown-based knowledge bases
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Agent Vault – Open-source credential proxy and vault for agents
Show HN Open-source credential management system that securely stores and proxies API keys and secrets for AI agents and automated systems.
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Honker – Postgres NOTIFY/LISTEN Semantics for SQLite
Show HN Brings PostgreSQL's real-time notification system to SQLite databases
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Built a daily game where you sort historical events chronologically
Show HN A daily puzzle game where players arrange historical events in chronological order to test their knowledge of history.
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Ghost Pepper Meet local meeting transcription and diarization
Show HN Local meeting transcription tool that identifies different speakers automatically
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Broccoli, one shot coding agent on the cloud
Show HN Cloud-based AI coding agent that generates complete code solutions in a single attempt
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WeTransfer Alternative for Developers
Show HN A secure file sharing platform designed specifically for developers to transfer code, assets, and project files easily.
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Backlit Keyboard API for Python
Show HN A Python library to programmatically control backlit keyboard lighting and effects
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Ctx – a /resume that works across Claude Code and Codex
Show HN A universal resume command that seamlessly works across Claude Code and GitHub Codex environments.
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GoModel – an open-source AI gateway in Go
Show HN Open-source AI gateway built with Go for routing and managing AI model requests
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VidStudio, a browser based video editor that doesn't upload your files
Show HN A privacy-focused browser video editor that processes files locally without uploads.
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Daemons – we pivoted from building agents to cleaning up after them
Show HN AI agent monitoring and cleanup service that helps manage and maintain autonomous AI systems.
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Mediator.ai – Using Nash bargaining and LLMs to systematize fairness
Show HN AI-powered mediation platform that applies Nash bargaining theory to resolve disputes fairly
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Holos – QEMU/KVM with a compose-style YAML, GPUs and health checks
Show HN QEMU/KVM virtual machine manager with Docker Compose-style YAML configuration and GPU support
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Run TRELLIS.2 Image-to-3D generation natively on Apple Silicon
Show HN Native Apple Silicon implementation of TRELLIS.2 for converting 2D images into 3D models
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A lightweight way to make agents talk without paying for API usage
Show HN A cost-free method for enabling AI agent communication without expensive API calls.
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A working reference implementation of context engineering
Show HN Reference implementation demonstrating context engineering patterns and practices for AI systems.
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Faceoff – A terminal UI for following NHL games
Show HN A command-line interface that lets you track live NHL hockey games and stats directly from your terminal.
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Plain – The full-stack Python framework designed for humans and agents
Show HN A human-friendly full-stack Python web framework optimized for both developers and AI agents.
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Prompt-to-Excalidraw demo with Gemma 4 E2B in the browser (3.1GB)
Show HN Browser-based AI demo that converts text prompts into Excalidraw diagrams using Gemma 4 model
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Shader Lab, like Photoshop but for shaders
Show HN A visual shader editor that makes creating and editing GPU shaders as intuitive as photo editing
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MDV – a Markdown superset for docs, dashboards, and slides with data
Show HN A Markdown extension that enables creating interactive documents, dashboards, and presentations with embedded data visualization capabilities.
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AI Subroutines – Run automation scripts inside your browser tab
Show HN Browser-based automation tool that runs deterministic scripts directly in tabs without API tokens.
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I made a calculator that works over disjoint sets of intervals
Show HN A web calculator that performs arithmetic operations on mathematical interval sets.
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Smol machines – subsecond coldstart, portable virtual machines
Show HN Lightweight virtual machines that start in under a second and can run anywhere.
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PanicLock – Close your MacBook lid disable TouchID –> password unlock
Show HN MacBook security tool that disables TouchID when lid closes, forcing password authentication for enhanced privacy protection.
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Sfsym – Export Apple SF Symbols as Vector SVG/PDF/PNG
Show HN Command-line tool to export Apple's SF Symbols as vector files in SVG, PDF, or PNG formats.
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Stage – Putting humans back in control of code review
Show HN A code review tool that prioritizes human judgment over automated processes for better development workflows.
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MacMind – A transformer neural network in HyperCard on a 1989 Macintosh
Show HN Implements a transformer neural network using HyperCard on vintage 1989 Macintosh hardware
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SPICE simulation → oscilloscope → verification with Claude Code
Show HN A workflow demonstrating electronic circuit simulation, oscilloscope measurement, and AI-powered code verification for hardware design validation.
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Home Memory – A local DB of my house, down to cables and pipes
Show HN A local database system to catalog and track everything in your home from furniture to hidden cables and pipes.
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Marky – A lightweight Markdown viewer for agentic coding
Show HN A minimalist Markdown viewer designed specifically for AI-assisted coding workflows.
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Libretto – Making AI browser automations deterministic
Show HN A framework that makes AI-powered browser automation more reliable and predictable for consistent results.
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Hiraeth – AWS Emulator
Show HN A lightweight AWS service emulator for local development and testing environments
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LangAlpha – what if Claude Code was built for Wall Street?
Show HN AI coding assistant specifically designed for financial industry workflows and Wall Street applications.
Apr 2026 TOP 10
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Smol machines – subsecond coldstart, portable virtual machines
Show HN Lightweight virtual machines that start in under a second and can run anywhere.
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OSS Agent I built topped the TerminalBench on Gemini-3-flash-preview
Show HN Open-source AI agent that achieved top performance on TerminalBench using Gemini-3-flash-preview
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Honker – Postgres NOTIFY/LISTEN Semantics for SQLite
Show HN Brings PostgreSQL's real-time notification system to SQLite databases
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I made a calculator that works over disjoint sets of intervals
Show HN A web calculator that performs arithmetic operations on mathematical interval sets.
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Tolaria – open-source macOS app to manage Markdown knowledge bases
Show HN Open-source macOS application for organizing and managing Markdown-based knowledge bases
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VidStudio, a browser based video editor that doesn't upload your files
Show HN A privacy-focused browser video editor that processes files locally without uploads.
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PanicLock – Close your MacBook lid disable TouchID –> password unlock
Show HN MacBook security tool that disables TouchID when lid closes, forcing password authentication for enhanced privacy protection.
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A Karpathy-style LLM wiki your agents maintain (Markdown and Git)
Show HN An AI agent-maintained wiki system using Markdown and Git for LLM knowledge management.
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Turning a Gaussian Splat into a videogame
Show HN Tutorial on converting Gaussian splatting 3D reconstruction into an interactive game using PlayCanvas engine.
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Auto-Architecture: Karpathy's Loop, pointed at a CPU
Show HN Automated CPU architecture optimization using Karpathy's learning loop methodology