Free, open-source game clipping for Windows.
Hit a key, keep the moment: instant clips, a built-in editor and one-click Discord sharing.
100% local. No account, no cloud, no watermark.

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Krak is in early development. There is no download yet: the first public beta is on its way.

Why Krak

• Always ready. The last seconds of gameplay are kept in memory. Press a key and they are saved instantly, no re-encoding.
• Light. Encoding runs on your graphics card (NVIDIA, AMD or Intel). The impact on your FPS should be invisible.
• Yours. Everything stays on your PC. Clips are plain MP4 files. Nothing is uploaded unless you decide to share it.
• Anti-cheat safe. Krak captures the screen like OBS or Discord do. It never injects into a game or reads its memory.
• Simple. Works out of the box. Advanced options are there, tucked away.

A clip is called a shard. Your library is the Glacier.

Roadmap to the first beta

• Krak identity, in 12 languages that follow Windows
• App foundation: settings, global shortcuts, tray icon, launch at Windows startup, single instance
• Glacier: shards sorted by game, favorites, search, rename, multi-select, built-in player, Recycle Bin
• Always-on replay buffer, encoded natively with NVENC on NVIDIA (H.264, HEVC), with Standard, High and Premium presets
• Continuous recording while the replay keeps working, safe from crashes
• Custom and stretched resolutions recorded as the screen shows them (or always stretched), the replay going on through Alt+Tab
• Screenshots, with their own page and a crop tool (copy the part you keep, or save it)
• Separate audio tracks: game and microphone, plus a mix that every player picks by default
• Editor: trim bar, waveforms, volume of each audio track, remembered per clip
• Export to a file, to the Glacier or to Discord under 20 MB, 50 MB or 500 MB, with an optional "by krak" badge, 4:3 clips stretched to 16:9, and vertical 9:16 for TikTok, Shorts and Reels (the frame placed in the editor)
• The Krak Discord one click away, and clips shared to its #clips from the app, opt-in (the app's side is ready; the community's bot opens it)
• Discord Rich Presence, with your Discord profile shown in the app (read from Discord itself, no login)
• Controller shortcut (Xbox controllers) with a buzz to confirm, and a second press that makes the last shard longer instead of a new one
• Game-only capture ("stream-proof"): only the game's window is filmed, found by itself or picked from the open apps, so overlays, notifications, Discord and the desktop never end up in a clip
• Choice of the captured screen, and the mouse cursor in clips (optional)
• Editor tools: cut a passage out, mute or bleep the mic or the game over a zone, slow motion, blurred zones, captions, all previewed live
• Easy to edit: zones dragged on the timeline (or S at the start and end), handles to adjust them, one key per tool, Ctrl+Z / Ctrl+Y in the editor and the best-of, and a shortcuts help
• Best-of: shards one after another as edited, cut, fade or flash transitions, an intro title, your music lowered under voices and action, 16:9 or 9:16, with a guided tour
• Markers: a shortcut marks a moment while you play, found again on the editor's timeline
• Collections: shards grouped by hand (a session, a tournament, a montage to come), the files staying where they are
• Making room: old heavy shards recompressed in Standard quality after a confirmation, the originals in the Recycle Bin, favorites never touched
• Installer and signed automatic updates
• Windows code signing (no SmartScreen warning)
• Native AMD and Intel encoders, separate Discord voice track

Later: local subtitles, importing clips from ShadowPlay / OBS / Medal, community translations.

Building from source

Requirements: Windows 10 or 11, Node.js 20+, Rust and the Visual Studio C++ build tools (Tauri prerequisites).

npm install
npm run tauri dev     # run the app with hot reload
npm run tauri build   # build the installer

tauri build also signs the in-app update files, so it needs the update signing key: set TAURI_SIGNING_PRIVATE_KEY to the key (or its path) first. Forks generate their own pair with npx tauri signer generate and put the public key in src-tauri/tauri.conf.json.

Releases are built by GitHub Actions: push a tag such as v0.2.0 (matching the version in tauri.conf.json) and a draft release is created with the installer and the signed update manifest. Windows code signing (SignPath) and VirusTotal scans of the installer are optional: docs/SIGNING.md explains how to turn them on, and what to do when Defender flags a release.

How capture works

The screen is read with DXGI Desktop Duplication, the same Windows API that OBS and Discord use, so nothing is injected into games. In game-only capture (or with the mouse cursor), Windows Graphics Capture films the game's window (or the screen) instead: no injection either, and nothing drawn over the window is recorded. Frames are encoded on the graphics card and the last seconds are kept in memory: on NVIDIA through the driver's NVENC directly (H.264, HEVC and AV1 where the card has it, with B-frames, lookahead and adaptive quantization), on AMD and Intel through Media Foundation, with a software fallback. If the encoder cannot keep up (a heavy game, a high frame rate), it switches to lighter settings on the fly instead of dropping frames. The video keeps the desktop's size: when a game switches the display to its own resolution (a stretched 1440x1080), its image is scaled into that frame the way the monitor shows it, so the stream and the replay go on through the change. Game sound comes from WASAPI loopback and the microphone from its own device, on separate tracks. Pressing the hotkey writes an MP4 straight from memory, without re-encoding. Continuous recording reuses the same encoded video and writes a fragmented MP4 as it goes, so a crash loses at most a second; screenshots are full-resolution PNGs of the same capture.

The quality presets and the measurements behind them (bitrates, tools, PSNR/SSIM, encoder speed) are documented in src-tauri/src/capture/quality.rs. The NVENC layer is a small C file compiled by cargo with the Visual Studio C++ tools, against NVIDIA's MIT-licensed nvEncodeAPI.h (src-tauri/native/nvenc); the NVENC library itself ships with the NVIDIA driver and is loaded at run time, never redistributed.

Built with Rust, Tauri and Svelte.

Translations

Krak speaks English, French, Spanish, Brazilian Portuguese, German, Italian, Polish, Turkish, Russian, Japanese, Korean and Simplified Chinese, and follows the language of Windows on first launch. English is the reference: every text lives in src/lib/locales/en.ts first.

To add a language:

1. Copy en.ts to src/lib/locales/<code>.ts (<code> is the language's two-letter code, like nl) and translate the values. Keep the {placeholders} as they are.
2. Add the plural forms your language needs next to each text that has a {count}: <key>.one, <key>.few, <key>.many… as named by Intl.PluralRules (the plain key is the "other" form).
3. Register it in src/lib/locales/index.ts, with its name written in that language.
4. Add the few texts the app shows outside its window (tray menu, file names) in src-tauri/src/i18n.rs, and the installer's language in bundle.windows.nsis.languages of tauri.conf.json.

npm run check fails if a translation misses a text. Until it is finished, type the file Partial<Strings> instead of Translation: the missing texts show in English.

License

Krak is free software, released under the GNU GPL v3.0. You can use it, study it, change it and share it. If you distribute a modified version, it must stay free and open source under the same license, with its source code available.

The Krak and Kryo Studio names and logos are not covered by this license. Forks must use their own name and logo: see TRADEMARKS.md and NOTICE.

Copyright © 2026 Kryo Studio.