Exported logos, signatures and screenshots often come with a wide empty margin: fully transparent pixels, or a white or light matte. Trimming it by eye takes patience. This tool finds the box that contains the real content, draws it on the picture as a dashed outline with the area outside dimmed, and saves only what is inside.
The point of showing the box is safety: automatic trimming can cut off pale parts of a picture, so you see what is kept before anything is saved. It runs in your browser and the image is not uploaded.
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Overview
About Auto Trim Image
Three kinds of border. Transparent trims pixels whose alpha is almost zero. Light treats a pixel as border if it looks white or nearly white when laid on white (so semi-transparent pixels are judged by how they look). Same colour as the corner trims a flat matte of any colour, such as black bars, by comparing each pixel with the top-left corner colour. "Automatic" picks transparent when the image has transparency and light otherwise.
Controls. Sensitivity is how far from the border colour a pixel must be to count as content: raise it to trim faint borders, lower it if content is being cut. Ignore dust requires a row or column to have more than a given number of content pixels before it counts, so a stray speck does not stop the trim. Padding keeps a few pixels of border around the content.
The result. The report shows the original and trimmed size, how much of the area was removed and how many pixels were cut from each side. Save as PNG or WebP to keep transparency, or JPEG (transparent pixels become white). The trimmed image is a copy of the pixels inside the box; nothing is resized.
Compatibility
Supported Formats
JPEG, PNG and WebP images up to 30 MB, 12,000 pixels on a side and 40 megapixels (decided by the content, not the name). Output: PNG, WebP (both keep transparency) or JPEG (no transparency).
Guide
How to Use Auto Trim Image
- Choose an image.
- Look at the dashed box. If content is cut off, lower the sensitivity; if a border remains, raise it or use "Ignore dust".
- Optionally add padding and choose the format.
- Download the trimmed image.
Highlights
Features
- Visible bounding box A dashed outline with the outside dimmed shows exactly what will be kept.
- Transparent, light or corner colour Handles transparent margins, white mattes and flat coloured bars.
- Dust and padding controls Ignore specks, keep a margin of your choice.
- PNG, WebP or JPG Keeps transparency where the format allows.
- Stays on your device No upload.
Applications
Use Cases
- Removing the transparent margin of a logo or icon exported with extra space
- Cutting the white border off a scanned or screenshotted picture
- Preparing a signature or stamp image so it aligns exactly when placed on a page
- Removing black bars from a screenshot
- Making product pictures the same tightness before placing them on a layout
Good to Know
Limitations
Border detection compares colours, not meaning. A very pale part of the picture (a white logo on white, a thin light line) can be treated as border and cut, and a noisy or JPEG-compressed border can look like content. That is why the box is shown before saving: always check it, and lower the sensitivity if anything is cut.
Soft or anti-aliased edges keep a few semi-transparent pixels. The tool only trims a rectangle around the content; it does not remove backgrounds inside the picture or rotate it. JPEG output has no transparency, so transparent areas are filled with white.
This tool runs entirely in your browser — your file is never uploaded to our servers. See our Privacy Policy for full details.
Support
Frequently Asked Questions
Is my image uploaded?
No. It is analysed and cropped in your browser. Nothing is sent to our server.
Could it cut off part of my picture?
It can, if part of the content is very close to the border colour. The dashed box shows what is kept before you save, and the sensitivity slider lets you correct it.
How do I trim a black border instead of white?
Choose "Same colour as the corner". It trims pixels close to the colour of the top-left corner, whatever that colour is.
A tiny speck stops the trim. What can I do?
Raise "Ignore dust": a row or column then needs more than that many content pixels to count.
Does trimming change the pixels inside?
No. The inside of the box is copied as it is, with no resizing or resampling.
Which format keeps transparency?
PNG and WebP. JPEG cannot store transparency, so transparent areas are filled with white.
Keep Going
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- Image Dimensions Checker See an image's width, height, aspect ratio, format and file size. The file stays on your device and is never sent to a server.
- Signature Background Remover Turn a photo or scan of your signature into ink on a transparent background. Automatic first, then erase and restore brushes to fix what it got wrong. In your browser.