Ahmet Yüksek

Installing

Windows

The Microsoft Store build is the easy one: verified by Microsoft, one click, and it keeps itself updated. The standalone installer from the download page works just as well, but Windows SmartScreen may say the publisher is unknown — there is no code-signing certificate behind it yet. Choose More info, then Run anyway. The installer needs no administrator rights and can add a desktop shortcut and Open with → CoolGorilla for image files.

macOS

Open the .dmg and drag CoolGorilla to Applications. On first launch, right-click the app and choose Open. If macOS says it is damaged, that is only Apple's quarantine flag: open Terminal, type xattr -cr followed by a space, drag the app onto the Terminal window and press Enter. It opens normally after that.

Linux

The AppImage needs no install. Make it executable — chmod +x, or right-click → Properties → Allow executing — then double-click it.

Opening photos

The window sizes itself to the first photo it shows, so a set of portrait frames opens in a portrait window rather than a letterboxed one.

What it opens

RAW from every major brand through LibRaw — Sony, Canon, Nikon, Fujifilm, Olympus, Panasonic, Pentax, Leica, Hasselblad, Phase One, Sigma, Kodak, Minolta, Mamiya, Leaf, Epson and Samsung — plus JPEG, PNG, TIFF, WebP, BMP and the HEIC files an iPhone shoots by default. Straight from the card, no conversion.

The window

The title bar carries the file name and your position in the shoot. Top right are two controls: a folder button that opens files, and the menu button — the same menu you get by right-clicking anywhere on the photo.

Along the bottom, the detail bar reads out the photo you are on:

Below the photo sits the filmstrip of thumbnails. Drag the divider above it to make it taller or shorter, drag its scrollbar or flick it to travel through a long shoot, and click any thumbnail to jump there.

Moving through a shoot

Navigation wraps around: past the last photo you are back at the first. A cold folder shows each photo's embedded preview immediately and sharpens to the real decode a moment later, so there is never a black frame to wait through.

Zoom, pan and lock-zoom

Past fit, CoolGorilla decodes the photo again at full resolution, so 1:1 really is 1:1 — which is what you want when you are checking focus on a RAW file.

Lock-zoom is for bursts. Zoom into the eye of the first frame, press Z, then arrow through the sequence: every frame of the same size holds the same crop, at full resolution, so you can compare the same detail across ten shots without touching the mouse.

Sorting

Menu → Sort orders the gallery by name, date modified or file size, ascending or descending, and remembers your choice. Star-rated photos always group at the front of the filmstrip — five stars first, down to unrated — whatever sort you pick; the sort orders photos within each of those groups.

Star ratings

Press 1 to 5 to rate the photo you are looking at; 0 clears the rating. The view moves on to the next photo by itself, and the one you just rated files into its star group at the front of the strip, where its stars show under the thumbnail.

Rate and file, in one keystroke

Hold Shift with a rating — Shift+1 through Shift+5 — and the photo gets that star and moves straight into an Approved\5Stars folder (or 4, 3, 2, 1) beside where it lives now. The rating travels with it, and the view moves on.

Use plain 1–5 when the stars are notes to come back to, and Shift+1–5 when the star is the decision: a shoot sorts itself into star folders as you go, with nothing left to move afterwards.

Ctrl+Z undoes the whole thing at once — the photo comes back to its folder carrying whatever rating it had before you pressed the key. It works on a photo that already has that rating too: pressing Shift+3 on a three-star photo is a request to move it, and it moves.

Filing a whole star group

Right-click any rated thumbnail in the filmstrip and you get two actions for its entire rating tier: move all of them to the matching Approved folder, or copy them there instead — the originals stay exactly where they are, keeping their stars, so you can assemble a print set without emptying the folder it came from. Both are a single undo, and copying the same group twice never overwrites: the second copy lands beside the first.

Approve, reject, delete — and undo

Approve and reject are deliberately non-destructive: the subfolder is created next to the photo and the file is moved, not copied or deleted. Its rating sidecar and any EXIF backup travel with it. A and X sit next to each other so one hand can cull while the other holds the coffee.

Undo steps back through everything you did to files in this session: ratings, approve and reject, rate-and-file, group moves and copies, rotations, and EXIF removal. A photo that has left the folder by other means — you moved it yourself, or emptied the subfolder — is skipped rather than failing loudly.

The copy set

The copy set is a running selection you paste somewhere else.

Rotating for print

R turns the photo a quarter clockwise, Shift+R anticlockwise. The file on disk is turned, not just the view.

Menu → Rotate also has the pass a print run needs. All landscape and All portrait turn only the photos facing the wrong way, so a mixed folder comes out uniform for the paper feed — photos already facing the right way are left untouched. Revert rotations puts the whole folder back the way it arrived, after the run.

Print size

Menu → Settings → Print size sets the resolution and unit used for the paper measurement in the detail bar. A lab working at 300 dpi in centimetres and someone preparing web images at 72 dpi want different numbers from the same file, so this is set once and remembered. Untick Show in the status bar to hide it again.

Properties and EXIF

Alt+Enter opens everything the file knows about itself: name, folder, type, pixel dimensions and megapixels, print size, bytes, modified and created dates — then the camera block: body, lens, aperture, shutter, ISO, focal length, exposure compensation and the moment it was taken.

Removing EXIF data

Menu → EXIF data → Remove EXIF data. Tick what should go — GPS location, camera, lens and serial numbers, capture settings, date and time, software, artist and copyright — and it is stripped from the open photo. Groups the file does not carry are greyed out, so you can see at a glance whether a photo is even carrying its location.

• Pixels are never recompressed. Only the JPEG's EXIF segment is rewritten; the compressed image data is copied through byte for byte.
• With the backup box ticked, the original EXIF is saved beside the photo. It travels with the file when you approve or reject, and goes to the Recycle Bin with it if you delete.
• Recover EXIF data puts it back from that backup. Unlike undo, it still works on a photo you stripped days ago.
• Don't show this dialog again makes later removals happen in one keystroke with the same choices. Bring the prompt back with Ask before removing EXIF in the same menu.

Opening in another app

Menu → Open in. The first time, pick your editor; it is remembered by name after that, and Change external editor swaps it. Give it a key in the shortcuts dialog and a photo goes to Lightroom or Photoshop with one press. Open with hands the photo to the system's own chooser for a one-off app, and L opens the photo's location — Explorer with the file selected, Finder on macOS, the containing folder on Linux. If another program rewrites a photo you have open, CoolGorilla notices when you come back to the window and reloads it.

Making the keys yours

Menu → Settings → Keyboard shortcuts. Double-click an action, or select it and press F2, then press the combination you want. Esc cancels, Clear leaves an action with no key, and Restore Defaults puts everything back. Changes take effect immediately — there is no restart.

• Actions with several keys — Next is the right arrow, PgDn, Down and Space — keep their alternates; only the first key changes.
• The rating keys 1–5 and Shift+1–5 are fixed and cannot be reassigned or taken by something else.
• A key already in use is refused the moment you press it, naming the action that has it.
• Remove EXIF data, Recover EXIF data, Open with and Open in editor ship with no key at all — assign them here if you use them often.

All keys

What CoolGorilla writes, and where

Nothing is written inside your photos except when you explicitly rotate one or remove its EXIF. Everything else lives beside them:

Preferences — sort order, print size, your shortcut changes, the remembered editor — are stored per user, outside your photo folders.

Updates

The version from this website checks for a new release on startup and offers it; turn that off under Settings → Check for updates on startup. The Microsoft Store version updates through the Store. Menu → What's new shows what changed in each release.