tooloora

Combine Images — side by side, stacked or as a grid

Join 2 to 20 photos into one image with the spacing, border and background you choose — locally in your browser, no upload.

Runs locally — nothing is uploaded

Drop images here or click

JPG, PNG or WebP · 2 to 20 images · stays local

Runs locally in your browser – no upload.

Drop in images and the preview appears here.

Combine images — side by side, stacked or as a grid

Drop in two to twenty images, put them in the order you want and choose whether they appear side by side, stacked or as a grid. You set spacing, border, background and output format, and the preview reflects every change immediately. The whole merge runs in your browser: no file is uploaded.

How do I put two photos side by side?

Drop both images, pick “Side by side”, leave “Same height” as it is, then combine and download. The first image in the list ends up on the left; the arrows next to each entry change the order, and they work with the keyboard too.

“Same height” scales every image to one common height without distorting it. With “Match to: smallest image” nothing is enlarged and larger images are scaled down. “Largest image” keeps the full resolution of the biggest photo and upscales the smaller ones, which can then look soft.

An example with two phone photos: a landscape shot of 4032 × 3024 and a portrait shot of 3024 × 4032 pixels. At the same height the portrait becomes 2268 pixels wide, so the pair measures 6300 × 3024 pixels, a little over 19 megapixels. That is more than Safari on iPhone and iPad will draw, so the tool scales everything down in the same proportion to 5908 × 2836 pixels (94 percent) and tells you before you export.

When is “Original size” the better choice?

When the pixels must stay untouched, for instance with screenshots you line up for a how-to. Every image keeps its size, and you decide whether smaller ones sit at the top, in the middle or at the bottom (when stacked: left, middle or right). The free space next to them gets the background colour or stays transparent.

How do I make a grid collage?

Pick “Grid”. The number of columns adjusts itself so the grid comes out as square as possible: 4 images give 2 × 2, 9 images 3 × 3, and with 5 images there are 3 on top and 2 below. All cells have the same size; their shape follows image 1, or you choose 1:1, 4:3, 3:4 or 16:9. Then you decide what happens inside a cell:

  • Fit shows every image in full. If its shape differs from the cell, a strip in the background colour remains.
  • Fill covers the cell completely and crops whatever sticks out from the middle, the way galleries on websites and social networks do.

If the last row is not full, you choose whether its images sit on the left, in the middle or on the right.

How big can the result be?

Two limits apply, and the tool respects both:

LimitValueReason
Longest side16,383 pixelsWebP stores width and height in 14 bits (Google’s WebP FAQ)
Area16,777,216 pixels (4096 × 4096)largest canvas Safari draws on iPhone and iPad (limit of the WebKit browser engine)

If either is exceeded, the whole picture shrinks in the same proportion, spacing and border included. Four phone photos in a 2 × 2 grid would measure 8064 × 6048 pixels and end up at 4728 × 3546.

Does “Longest side at most” limit the width?

No, it caps the longer of the two sides, and for a stacked collage that is the height: two square photos stacked with “1080 px” become 1080 pixels tall but only 540 pixels wide. If you need a specific width, export at full size and set it afterwards with resize image. If the file is then still too large for an upload limit, use compress image.

According to its Help Center, Instagram scales photos down to at most 1080 pixels wide and crops them if the aspect ratio falls outside 1.91:1 to 3:4 (as of October 2026). Two squares stacked (1:2) would be cropped there, four in a 2 × 2 grid (1:1) would not.

JPG, PNG or WebP?

FormatTransparencyCompressionGood for
JPGnolossy, adjustable qualityphotos
PNGyeslossless, larger filescreenshots, graphics, logos
WebPyeslossy, adjustable qualityimages for the web

If every input is a JPEG photo, the tool suggests JPG, otherwise PNG. If you choose a transparent background and save as JPG, the chosen colour fills the free space, because JPG has no transparency.

Honest limits

  • HEIC photos from an iPhone are not accepted directly. Convert them first with HEIC to JPG, which also works without an upload.
  • At most 20 images per run. On export every file is read once at full resolution and released straight away; on older phones that takes a few seconds with many large photos.
  • Metadata is dropped: the result is a newly encoded image, so EXIF data including the GPS position of the individual photos is not carried over.
  • Free positioning or rotation is not available here. Fix tilted or loosely framed photos first with rotate image or crop image.

Frequently asked questions

Are my images uploaded to combine them?

No. Reading, arranging and encoding all run in your browser; no file leaves your device. On export every image is read once at full resolution and released straight away, so even twenty large phone photos do not fill up the memory.

How do I combine images of different sizes?

With “Same height” (side by side) or “Same width” (stacked) every image is brought to one common measure without distortion. “Smallest image” enlarges nothing and scales the big ones down, “Largest image” keeps the full resolution of the biggest one and upscales the smaller ones. With “Original size” each image stays as it is, and you align it to the top, middle or bottom.

How do I make a grid collage?

Choose “Grid”. The columns adjust themselves to a grid that is as square as possible (4 images give 2 x 2, 9 give 3 x 3), and you can also set them by hand. The cell shape follows image 1 or is 1:1, 4:3, 3:4 or 16:9. “Fit” shows every image in full, “Fill” covers the cell and crops whatever sticks out from the middle.

Why is the result smaller than expected?

Because two limits apply: at most 16,383 pixels per side, since WebP stores width and height in 14 bits (Google’s WebP FAQ), and at most 16,777,216 pixels of area, the largest canvas Safari draws on iPhone and iPad. If either is exceeded, the tool scales everything down in the same proportion, spacing and border included, and shows you the full and the actual size before you export.

Which format should I pick?

JPG for photos: small files but no transparency, so a transparent background is filled with your chosen colour there. PNG for screenshots and graphics: lossless and with transparency, but larger. WebP does both and, according to Google’s WebP compression study, comes out 25 to 34 percent smaller than JPEG at comparable quality.

Can I combine iPhone photos in HEIC format?

Not directly: the tool accepts JPG, PNG and WebP. Convert HEIC files first with this site’s HEIC to JPG converter, which also works without an upload. Each run takes two to twenty images.