"Let's build the fastest image viewer in the world." — and that's exactly what we did.
BoltView is a Windows image viewer built around one thing only: speed. It's faster than any image viewer out there.
Most viewers aren't slow because of the time it takes to read a file — they're slow because of the time it takes to decode the compression in JPEG and PNG files.
BoltView was redesigned from scratch on one principle: "never decode at the moment you need to display." That erased the wait when you flip through photos.
Click, and it's already on screen. The next photo shows up instantly.
▶ Why it's the fastest
· Prefetch decoding: the images before and after the one you're viewing are decoded in the background and kept ready in memory. ← next/previous is instant
· GPU rendering (Direct2D): zoom, pan and rotation are handled by your graphics card, so every screen transition finishes in a single frame.
· LRU memory cache: an image you've already seen is never decoded again.
· libjpeg-turbo acceleration: decodes JPEG 2-4x faster with SIMD.
· Parallel thumbnails + OS cache reuse: gallery thumbnails fill in the blink of an eye.
▶ Key features
· Gallery (browse) start screen: folder tree on the left + thumbnail grid, pinned favorites and recent folders, multi-select with drag / Ctrl / Shift
· Viewing: fit / 100% / fill, cursor-anchored wheel zoom, rotate/flip, automatic EXIF rotation, animated GIF
· File actions: delete to Recycle Bin, copy, save as (lossless JPEG rotation), set as desktop wallpaper, open file location
· 4 themes: Dark / Light / Black (OLED) / Night (sepia) + auto match system
· 4 languages: Korean / English / Japanese / Chinese (auto-detects system language)
· Slideshow, filmstrip, info panel, full keyboard shortcuts, DPI-aware
▶ What it's built with
· C++17 / Win32 API (native, lightweight)
· Direct2D (GPU rendering) · WIC (decoding) · DirectWrite (text)
· libjpeg-turbo (JPEG acceleration)
· No external runtime to install, single executable
▶ Install / Download
· Installer: BoltView-Setup.exe (auto file association + shortcuts)
· Portable: BoltView-portable.zip (unzip and run BoltView.exe)
· Supported: Windows 10 / 11 (64-bit)
▶ Essential shortcuts
←/→ previous·next · wheel zoom · F fit to screen · F11 fullscreen · Space next · Del delete · Esc back to gallery/close
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[ Frequently Asked Questions (FAQ) ]
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Q. Is it really the fastest?
A. Yes, it's the fastest image viewer available today. With prefetch decoding + GPU rendering + LRU cache + libjpeg-turbo combined, cached photos switch within a single frame (about 16ms).
Q. Is it free?
A. Completely free. A no-install portable version is available too.
Q. What formats does it support?
A. JPEG, PNG, GIF (animated), BMP, WebP, TIFF, ICO, HEIC and more (HEIC requires the Windows codec).
Q. Can I set it as my default image viewer?
A. Yes, from the app under [Settings > System > Set as default image viewer].