How to use

1. Add text or an image

Type text and choose “Start editing,” or load one file with “Choose a file.” Text files may be .txt, .json, .csv, or .md. Images may be PNG, JPEG, or WebP. Text and files must be 25 MiB or smaller, and images must be no larger than 24 megapixels. Text files may use UTF-8, Shift_JIS, or UTF-16 with a byte order mark. Some devices can only handle smaller images.

On the input screen, you can paste text or an image, or drop a file. While editing, choose “Change input” to select another item. Pasting or dropping while editing asks before replacing the current input.

2. Select what to hide

Drag across text to select it. On a touch screen, select the text and then tap “Hide selection.” Drag over an image to select a rectangular area. Ranges are not detected automatically, so select each detail you want to hide. Use the zoom controls in the image editor to change its display size.

Remove a range with its remove button in the list. Choose replacement text for text ranges; an empty value uses [MASK]. Selected image areas are filled with black.

3. Review and export

Reviewing the result before export is optional. Copy the masked text or save it as a TXT file. Copy and save always contain only the result with selected ranges replaced.

Preview a masked image and save it as PNG. The output keeps the original dimensions, composites transparent pixels onto white, then fills selected areas with opaque black. Original image metadata is not carried over. Copying images is not supported.

Undo, redo, and reset

Adding or removing a range, changing replacement text, and resetting are recorded in the edit history. Use “Undo” and “Redo” to move through it. When focus is not in a text field, press ⌘ / Ctrl + Z to undo, and ⌘ / Ctrl + Shift + Z or ⌘ / Ctrl + Y to redo.

“Reset” closes the current input, clears its ranges, and restores the replacement text to its default value, [MASK]. You can still undo from the input screen to restore the input and its edits. When at least one range is selected, choosing a new input asks for confirmation; confirming discards the previous input and its history, so you cannot undo back to it. With no selected ranges, the new input replaces it without confirmation and the previous input and its history are discarded.

How your data is handled

Your text, images, ranges, and edit history are processed in your browser and are not sent elsewhere. Only the theme preference is saved on your device. Input data and edit history are not kept after you leave the page. Automatic detection, OCR, and PDF input are not supported.