What's the difference between border and inner margin?

Border is the colored outermost ring. Inner margin is extra space between the border and the image; coloring it gives you a mat like a real picture frame. Set both to zero to keep the image as-is. Set border=0 plus a white inner margin for a polaroid look.

How does the output size change?

The original width and height get `(borderWidth + innerMargin) × 2` added. For a 1000×800 image with border 6 px and inner margin 40 px, the output is 1092×892.

JPEG turned my transparent area black

JPEG has no alpha channel. Set the inner margin to a solid color, or pick PNG / WebP instead.

The border is too thick

Try the 『Thin 4 px』 or 『SNS padding 32 px』 preset. The slider goes 0–200 px. As a rule of thumb, keep border thickness below 5–10% of the image's shorter side.

What if I also want rounded corners?

Use the image-rounded-corners tool after adding the border, or before. They chain cleanly: borders first → download → round corners after.

Back to Image

Image border — add a frame with custom width, color, and inner margin

Add a clean border (and optional inner mat) around an image. Pick the border width (0–200 px) and color (HEX), and an inner margin (mat) that sits between the border and the image. Great for SNS posts, portfolios, and presentation assets. Outputs PNG (transparent), JPEG, or WebP with a quality slider. Everything is composited with Canvas in your browser — no upload.

imagewatermark

How to use

Drop an image, then pick a border width (0–200 px) and color (HEX). Optionally add an inner margin between the border and the image — fill it with a color to get a photo-mat or polaroid feel. Choose a preset (Thin / Polaroid / Photo mat / SNS padding) for a one-click look. Outputs PNG (transparent) / JPEG / WebP. Canvas-only — even large images render in a couple of seconds.

FAQ

What's the difference between border and inner margin?: Border is the colored outermost ring. Inner margin is extra space between the border and the image; coloring it gives you a mat like a real picture frame. Set both to zero to keep the image as-is. Set border=0 plus a white inner margin for a polaroid look.
How does the output size change?: The original width and height get `(borderWidth + innerMargin) × 2` added. For a 1000×800 image with border 6 px and inner margin 40 px, the output is 1092×892.
JPEG turned my transparent area black: JPEG has no alpha channel. Set the inner margin to a solid color, or pick PNG / WebP instead.
The border is too thick: Try the 『Thin 4 px』 or 『SNS padding 32 px』 preset. The slider goes 0–200 px. As a rule of thumb, keep border thickness below 5–10% of the image's shorter side.
What if I also want rounded corners?: Use the image-rounded-corners tool after adding the border, or before. They chain cleanly: borders first → download → round corners after.

Related tools

Image Rounded Corners

Round the corners of an image and export as transparent PNG / JPEG / WebP. Radius is set in pixels (up to half of the shorter side), and each corner (TL / TR / BR / BL) can be toggled independently to make half-circles, capsule shapes, or one-side rounded cards. Background defaults to transparent (PNG/WebP) or can be filled with any color (required for JPEG). Useful for SNS profile pictures, app icons, card thumbnails, and shadcn-style UI assets. Runs entirely in the browser — nothing uploaded.

imageformat

Image watermark — overlay text or image at 9-grid position

Overlay a text or image watermark onto your photos. Composited via Canvas entirely in the browser. Choose position (9-grid), size, opacity and margin. Batch-process and download as a single ZIP. Output keeps the original format (PNG / JPEG / WebP).

imagewatermark

Image collage — grid / horizontal / vertical layout

Combine multiple images into one — as a grid, a horizontal strip, or a vertical strip. Composited via Canvas entirely in the browser. Tune columns, gap, padding, background color and output format (PNG / JPEG / WebP). Reorder with up/down buttons.

imagemerge

Convert AVIF photos to JPG / PNG / WebP — compatible everywhere

Decode .avif images with the browser-native AVIF decoder and re-encode them as JPEG / PNG / WebP. AVIF is great for the web but older Safari versions, email clients, Slack and Office still can't preview it — convert before sending. Batch conversion with single-click ZIP download is supported. Files never leave your device — everything runs in the browser.

imageconversion