Paste and go. Copy a screenshot, press ⌘V, and the document is built around it at its own size.
Assemble several images on one canvas.⇧⌘V drops a pasted image onto the document you already have instead of starting a new one, and Place image (I) takes several files at once. Each one arrives selected — drag it where it goes, or pull a handle to resize it.
Make room for them. The gear menu's Canvas size grows or crops the artboard without touching what is on it — anchored top left, so the screenshot you have already marked up does not move and the new space appears where you want to paste. New document starts a blank one at whatever size you need.
Annotate. Arrows, boxes, rounded boxes, ellipses and lines, with an optional fill and dashed or dotted outlines.
Numbered steps. Drop badges that count themselves — 1, 2, 3 — for "do this, then this". Deleting one does not renumber the rest.
Text that survives a busy background. A plate behind the block, plus font, size and alignment.
Redact and pixelate. Both bake into pixels. A box drawn over a password is not a layer someone can switch off later — the original is gone.
Change a color. Pick a color off the picture and move three sliders — hue, saturation, brightness. Only the pixels matching that color change, and matching is perceptual, so one fuzziness setting behaves the same on a dark navy as on a pale cream.
Select the material, not the rectangle. Drag across an object and the selection floods outward through pixels of the same color, stopping at edges. Or paint the area in by hand with a soft brush.
Non-destructive. Color work lives on adjustment layers above the picture. Nothing is baked until you export, and hiding the layer gives you the original back.
Crop to a free box, a ratio, or an exact size.
Keeps what the file came with. EXIF, and the parameters an image generator writes into a PNG, are read on import, shown in the Metadata panel, and put back into the file you export.
Several documents at once, as tabs across the top.
See the Keyboard tab for every shortcut.
Where your data lives
Your documents live in your browser's IndexedDB, on this device and this browser only, with preferences in sessionStorage. Nothing is uploaded anywhere, and the app works with the network switched off.
Documents go to IndexedDB rather than sessionStorage because a marked-up screenshot carries the image itself, which blows the 5 MB sessionStorage ceiling on the first paste.
This is the whole database. If you clear site data, use a private window, switch browsers, or lose the device, it is gone. Back up regularly.
Backing up
Export PNG writes a flattened image of the visible layers — that is the file you send to somebody. It carries the metadata the source image arrived with, unless you turn that off in the Metadata panel.
Copy puts the same image straight on the clipboard, which is the quicker route most of the time.
Neither is a backup of your editing state: layers, adjustment layers and the undo history are not in a PNG. Use the topbar's export for a full .pumapack backup you can import again.
Clear all local data
Danger zone. This erases every PumaMarkup record in this browser. Export a backup first.
Type DELETE EVERYTHING to confirm:
?
Open this help
Esc
Close a dialog, or cancel the stroke or crop in progress
⌘V
Paste an image as a new document
⇧⌘V
Paste an image onto this document, placed and selected
⌘Z / ⇧⌘Z
Undo / redo
⌘0
Fit the artboard to the window
BMHE
Pen · Marker · Highlighter · Eraser
AROL
Arrow · Rectangle · Ellipse · Line
T / N
Text / numbered step badge
I
Place image — choose one or several files and drop them on this document
X / Y
Redact / pixelate — drag a box
C
Crop — Enter applies, Esc cancels
\
Clean view — every overlay off, so the canvas shows what an export would write
⌥
Hold to pick a color off the picture for the recolor
⇧
Constrain a shape to a square, circle or 45°, or hold for a before / after of the recolor
Space-drag
Pan. Right-drag or middle-drag pans too, in any tool
Wheel
Zoom about the pointer. Two-finger scroll pans
About PumaMarkup
PumaMarkup is a rebuilt branch of PumaDraw, tuned for quickly marking up paste-in/copy-out screenshots. Common tools (mosaic, redact, callouts) on the top level. Auto-incrementing counter stamp makes process documentation easy. Also has a unique(as far as I know) area and color masking engine made for quick H/S/B adjustments.
About PumaWorx
PumaWorx is a suite of offline, single-HTML productivity apps that run entirely in your local browser. The entire suite is a personal, open source vibecoding project.