A free, browser-based pixel-art editor for voxel-game block textures - paint in 2D, see it on a live 3D block, and export packs for Minecraft, Tiled, and the indie engine stack. No account, no install.
Hexcalibur is a free, browser-based pixel-art editor purpose-built for voxel-game block textures - think Minecraft resource packs, Tiled tilemaps, and indie engines like Godot, Unity, Three.js, and Babylon. You paint in 2D and watch the texture wrap a rotating 3D block as you work, then export a correctly structured pack for your engine in one step.
It is the project in my portfolio that goes deepest on UX: a professional-grade creative tool with hundreds of interaction decisions, plus the marketing site at hexcalibur.io, a documentation site, and an MDX blog. It launched publicly on July 12, 2026 as a freemium product with accounts, cloud sync, and a paid Pro plan. In October I relaunched it as a fully free, local-only tool with no accounts at all - every feature unlocked, and nothing leaving the user's browser.
Pixel artists who make textures for 3D voxel games have a fundamental problem: they paint on a flat 2D canvas, but their work lives on the faces of 3D blocks. Seams, tiling errors, and lighting issues only show up after a slow export-and-import round trip into the game engine.
Hexcalibur closes that loop. You paint in 2D and watch the texture update on a rotating 3D block in real time - across multiple block arrangements, so you catch tiling seams the moment you paint them. Around that core insight I built the product strategy:
.hexc pack file is the backup and transfer format - a ZIP of layer PNGs and a JSON manifest that round-trips layers, frames, tags, and palettes intact..hexc archive and every engine export
A creative tool is thousands of small interaction decisions, and each one either builds or erodes the user's trust.
The editor uses a five-region layout: top menu bar, left tool rail, an asset switcher panel, a resizable 2D-canvas / 3D-preview split at center, and a right panel for color, palette, and layers. Every horizontal footer shares the same height so bottom edges align into a single visual baseline. The 3D preview is always visible and never collapsed - it is the product's reason to exist, so it is never more than a glance away. Right-panel sections can be shown, hidden, resized, or detached into floating windows that share one drag-and-resize system with a consistent grammar.
Sixteen tools, ordered into three clusters - transform, selection, paint - with no divider lines; the icon shapes themselves carry the grouping. Ordering is deliberate: the Tile Stamp sits directly after Fill so that in tilemap mode the enabled tool set reads as one unbroken run instead of scattering active tools among dimmed ones. Occasional tools park at the bottom, following conventions users already know from Photoshop - including keyboard shortcuts (B for brush, M for marquee, L for lasso).
New users get a guided, per-surface tour system - 4 steps in the pack browser and a 21-step editor tour that walks the tool rail, color and palette systems, layers, the 3D preview, importing, and a continuous deep-dive through the export dialog for each game engine. Shorter tours cover the animation timeline and tilemap mode, each triggering the first time the user reaches that surface and replayable from the Help menu. A firm rule I held: tour demo content is always synthetic and visual-only - a tour must never mutate the user's real work.
Complex features stay out of the way until relevant. The animation timeline is completely hidden for single-frame assets - no vertical tax on users who just want to paint a block. Tilemap tooling lives in a tile shelf that only appears for tile-based packs. Mirror mode (paint one face, all faces update) defaults on for first-timers because most block textures are uniform - and turning it back on after faces have diverged is guarded by a confirmation dialog, and undoable.
The marketing site at hexcalibur.io is a bespoke, conversion-focused build - video-led, structured on AIDA with the strongest differentiator first so the core value lands within five seconds. It runs from the hero ("Paint in 2D. See it in 3D.") through the problem statement, three differentiator deep-dives (the 3D preview, packs, and engine exports), animation, tilemaps, a feature grid, an audience self-select, a plain-English mechanics section, a zero-JavaScript FAQ, and a final CTA band.
The conversion mechanics:
Hexcalibur launched with a full SaaS around it: accounts (password, Google, and magic link, with TOTP two-factor), Supabase cloud sync, a Pro plan at $5/month, $29/year or $59 lifetime sold through Polar as Merchant of Record, transactional email, and a first-party analytics pipeline with an internal metrics dashboard. The free tier was a real product, not a demo - and Pro gates appeared softly, only when a gated control was actually touched.
Building that taught me a lot about billing, entitlements, and funnel design. But Axidus was becoming a different business for a different audience, and a hobbyist tool for pixel artists and indie game developers didn't need a paywall or an account system around it. So in October I split Hexcalibur out into its own repo and brand and released it as v2.0.0: free, local-only, and account-free. Every feature was unlocked, the accounts, billing and cloud sync came out, and the .hexc pack file stayed as the way to back up and move work. The editor, site and docs moved to hexcalibur.io, with redirects from every old address, and the marketing site was rewritten for the new promise - "Free, every feature. Works in your browser. No account needed."
Hexcalibur began as HYBRUSH, a v1 prototype aimed at a single game platform. When that platform shut down, I rebranded, repositioned around the engines people actually ship to, and rebuilt it. Major post-launch rounds shipped an animation timeline with onion skinning and tagged loops, a full tilemap mode with autotiling and terrain generation, custom canvas sizes up to 512x512, the lossless .hexc file format, cross-asset clipboards, and the unified export dialog - each round including its own onboarding tour, documentation, and website updates so product, education, and marketing never drift apart. In October 2026 it became the free, standalone v2.0.0.