Borderless Window

A lightweight client-side mod for NeoForge 1.21.1 that adds borderless fullscreen to Minecraft, replacing the exclusive fullscreen toggle with a proper 3-mode system — plus a configurable FPS overlay.

Features

• Three screen modes: Windowed, Borderless, and Minecraft's regular exclusive Fullscreen.
• Configurable F11: choose what the key does — toggle Borderless, toggle exclusive Fullscreen, or cycle through all three modes.
• FPS overlay: Simple mode shows the current FPS; Extended mode shows a single line with the current FPS plus the Min / Avg / Max over the last 15 seconds. Position configurable (any screen corner). Stats sample the game's own FPS counter, so they always match F3 and respect VSync / FPS caps. Auto-hides while F3 is open.
• Config screen included: change everything from the Mods menu (select the mod → Config button). No other mod needed.
• HDR-friendly: avoids the black-screen flash / color profile switch that exclusive fullscreen (and naive borderless implementations) cause with Windows HDR enabled.
• Multi-monitor aware: borderless and fullscreen apply on the monitor the window is currently on, not always the primary one.
• Persistent: all settings are remembered between game sessions (config/borderlesswindow.json).
• Sodium integration (optional): with Sodium 0.8.x installed, the "Fullscreen" checkbox in its video settings is replaced by a "Screen Mode" selector, and the mod's own section gains the "F11 Mode" and FPS overlay options. Built entirely on Sodium's official Config API — no fragile mixins into Sodium internals. Also plays nice with Reese's Sodium Options.
• Zero required dependencies: works with or without Sodium.
• Translatable: all strings live in standard lang files (en_us, es_mx, es_es included — contributions welcome).

Why borderless?

Exclusive fullscreen changes your monitor's actual display mode, which causes slow alt-tabbing, black-screen flashes with HDR, resolution desync bugs, and broken window states when the game restarts. Borderless fullscreen is just a window sized to your monitor with no decorations: it looks identical, but alt-tab is instant and nothing ever desyncs.

Configuration

• In game (no Sodium): Mods menu → Borderless Window → Config. Four options: Screen Mode, F11 Mode, FPS Overlay, and FPS Overlay Position. Changes apply instantly.
• In game (with Sodium): Video Settings → the "Screen Mode" option (replaces Sodium's fullscreen checkbox) and the "Borderless Window" section for the F11 Mode and FPS overlay options.
• Config file: config/borderlesswindow.json. If the mod ever gets stuck in a weird state, delete this file and restart — defaults are regenerated safely.

Requirements

• Minecraft 1.21.1
• NeoForge 21.1.x
• (Optional) Sodium 0.8.0+ for the video settings integration

License

MIT