RunLocalTools

Merge Images Online — Combine Photos Side by Side, Stacked or in a Grid

Merge images into one picture in your browser — horizontal, vertical or grid. Rotate, crop, add captions, export PNG, JPEG, WebP or PDF. Free, no upload.

What it does

Merge Images combines two or more pictures into a single image. Line them up side by side, stack them top to bottom, or arrange them in a grid, then download the result as PNG, JPEG, WebP or a one-page PDF. Browsers that can encode AVIF also get it as an option.

It is built for the jobs people actually have: before-and-after shots, Instagram carousel strips, stitched screenshots, product photo rows and quick collages. You can rotate, flip, crop and caption each image, set the gap, padding, background, rounded corners, border and shadow, and pick a size preset such as Instagram portrait, X/Twitter, Open Graph or A4 at 150 or 300 DPI.

How it works

Your browser decodes each image and the tool draws them onto a canvas at the positions the layout calculates. Rotation, flipping and cropping are applied during that draw, so nothing is re-compressed until you export. The live preview is rendered at a screen-friendly size for speed; the download is rendered at full resolution. If the finished image would be larger than your browser’s canvas limit, the tool can scale it down automatically (or refuse and tell you, if you turn auto-downscale off).

How to use it

  1. Add images. Click the drop area, drag files anywhere on the page, or paste from the clipboard.
  2. Put them in order. Drag to reorder, use the arrow buttons, or sort by name, size, date or dimensions. Undo and redo cover every list change, including Clear all.
  3. Choose a layout. Pick horizontal, vertical or grid, then decide how mismatched images are sized: original sizes, match the tallest or shortest, a fixed height or width, or uniform cells with contain, cover or stretch.
  4. Edit and style. Rotate, flip, crop or duplicate individual images, add captions if you want them, and adjust gap, padding, colours, corners, border and shadow.
  5. Set the output. Leave it on Auto or choose a size preset, then pick the format, quality and scale. The page shows the final pixel size and an estimated file size.
  6. Export. Download the file, copy it to the clipboard as a PNG, or save a PDF.

Need to prepare images first? Crop, Resize or Rotate / flip them before merging. Phone photos in HEIC can be opened with Open/Convert HEIC Files. After merging, Compress shrinks a large file, and Format converter switches formats. If you want a ready-made photo sheet instead, try Contact sheet / collage; for comparing exactly two images with a slider you can share, use Before / after slider. To bundle pages rather than pictures, see PDF merge / split.

Frequently asked questions

Are my images uploaded anywhere?

No. Your images are read and combined inside your browser tab, and the merged result is created on your device. See the Privacy section below for the two optional features that download a helper library.

How do I merge images that are different sizes?

Use the Image sizing option. “Original sizes” keeps every image as it is and aligns them. “Match tallest” or “Match widest” scales the others up, and “Match shortest” or “Match narrowest” scales them down, always keeping aspect ratio. “Fixed” sets an exact height or width. “Uniform cells” places each image in an equal box using contain, cover or stretch (stretch is the only option that distorts).

What is the largest image I can make?

It depends on your browser. Desktop browsers generally allow up to 16,384 pixels per side and about 268 megapixels in total; iPhone and iPad browsers allow roughly 16.7 megapixels. The tool shows the final size as you work and, by default, scales oversized results down instead of failing.

Why did my download come out as a different format, or with a white background?

JPEG cannot store transparency, so transparent areas are filled with white. And some browsers cannot encode certain formats, such as AVIF; in that case the tool saves a PNG instead and tells you. Choose PNG or WebP to keep transparency.

Can I make an Instagram carousel?

Yes. Choose the Instagram carousel preset and the tool places your images in one strip with a 1080×1350 slide for each image.

Will my images still be there if I close the tab?

Usually, yes. The tool keeps your images, their order and your per-image edits in your own browser’s storage so you can pick up where you left off. Use Reset tool to delete them. Private-browsing windows and cleared site data will remove them.

Privacy

Merging is local. Decoding, layout, preview, rotating, flipping, cropping, captions and the PNG, JPEG, WebP and AVIF exports all run in your browser, and your images are never sent to a server. Copying to the clipboard is local too. Saved images, order and settings stay in your browser’s own storage on your device.

Two features optionally use the internet, and only when you use them:

  • HEIC photos: the first time you add a HEIC/HEIF file the browser can’t open itself, the tool downloads a small decoder library from a public CDN (jsDelivr). Your photo is still converted on your device; only the library is fetched.
  • PDF export: the first time you click PDF, the tool downloads the jsPDF library from a public CDN (cdnjs). The PDF is still built on your device.

If you are offline or never use those two features, nothing is fetched.

Supported formats and limitations

  • Input: JPG/JPEG, PNG, WebP, GIF, BMP, SVG and HEIC/HEIF, plus AVIF where your browser can decode it. Animated GIFs are merged using their first frame. SVGs are rasterised, at about 1024 px on the long side if they are smaller.
  • Output: PNG, JPEG and WebP everywhere; AVIF only in browsers that can encode it. PDF is a single page.
  • Size limits: set by your browser’s canvas limits (see the FAQ); phones are lower than desktops.
  • Preview: shown at reduced resolution for very large results; the export is always full quality.
  • Shadows: can be clipped at the edge of the canvas unless you add outer padding.
  • Before / after view: a preview-only comparison for exactly two images; it is not exported.