Support

How does the automatic layout work?

Load a folder of photos and the app automatically distributes them across as many pages as needed, generating a randomised mosaic-style layout for each page. You can then freely adjust any page afterward — move, resize, or swap individual photos, add frames or text boxes, and fine-tune anything you like.

My photos are being cropped or cut off — how do I fix that?

You have several options in the Photo Fit panel. For no cropping at all, switch Photo fit to Jigsaw (whole photos fitted together, no gaps) or Fit whole photo (each photo shown in full with background around it). If you prefer the classic mosaic but want it kinder to your photos, keep Fill frame and turn on Match photos to frame shapes (puts each photo in the best-fitting frame, roughly halving how much is cropped) and Keep the subject in view (centres any crop on the face/subject rather than the middle). The Maximum crop slider lets you cap how hard any photo may be cropped. And you can always click a photo and drag or scroll to reposition its crop by hand.

Where's my photo list / the page thumbnails?

They're in the bar along the bottom of the window, with two tabs — Photos and Pages. Click a tab to switch between them, and use the ▾ button at the right of that bar to collapse it for more canvas space. The left-hand settings panel groups into sections too — click any section heading to fold it away.

What photo formats are supported?

JPEG, PNG, WebP, TIFF, and BMP are fully supported on both Mac and Windows. HEIC/HEIF photos (the default format for recent iPhone photos) are also supported on Mac, since macOS can decode these natively — on Windows, HEIC/HEIF photos aren't supported and will be skipped, since that decoding support isn't available on that platform.

What page size should I use for a photobook?

Photobook services rarely use exact ISO paper sizes — an "A3" photobook usually isn't 420×297 mm. Use the size the service itself specifies, entered as a custom size in millimetres at 300 DPI, and check whether they want a single page or a double-page spread (a spread is roughly twice the width). The Help guide lists the sizes and margins I've tested with Photobox, Printerpix and Mixbook. Whichever service you use, order a test print before laying out a large book — book sizes and printing software do change over time.

How do I export or print my collage?

Use Export Page or Export All to save your pages as JPEG images (or a ZIP of JPEGs for multiple pages). To print, use the Save for Printing option, which prepares your pages for you to print from Preview.

Where are my exported files saved?

You'll be asked to choose a save location each time you export, print, save a session, or create an archive — nothing is saved automatically to a fixed location.

Can I save my work and come back to it later?

Yes. Use Save to store your current project as a session file, and Restore to reload it later. Use Archive to bundle your project together with copies of the photos themselves into one portable file — useful if you want to move a project to another computer. You can also save a layout as a Template, without photos, to reuse the same design with a fresh set of photos.

Does this app use the internet or collect any data?

No. Mosaic Collage Maker works entirely offline and does not collect, transmit, or share any data. See the Privacy Policy for full details.

What are the system requirements?

Mosaic Collage Maker runs on macOS and Windows. For best performance with very large photo libraries (hundreds of photos across many pages), a computer with sufficient available memory is recommended.

Which chats can I make a Chat Book from?

WhatsApp and iMessage conversations — one-to-one or group. You bring the chat in from an export file, and the app turns it into a Keepsake book or a numbered transcript. See the Chat Book guide for full steps.

Is my chat uploaded anywhere for Chat Book? Do I need an account?

No, to both. The export file is read entirely on your own computer — the app makes no network connections, there's no account and no cloud, and nothing is tracked. Your conversation never leaves your machine. That's a deliberate difference from the print-and-ship chat book services, which process your chat on their servers.

How do I make a book from iMessage?

Apple's Messages app has no export button, so you use a desktop tool that reads the chat from your iPhone backup. We use iMazing: open the conversation, export it as Text (it saves a .txt file plus a folder of the photos), then in the app click 💬 Chat Book…, pick the .txt, and choose its attachments folder when asked. The same route works for WhatsApp chats, and usually keeps more of your older photos.

Some of my older WhatsApp photos are missing from my Chat Book — why?

WhatsApp limits how much media it puts in an export, so older photos in a long chat are sometimes left out by WhatsApp before the file ever reaches the app. Where that happens the book shows a small "photo not included" marker, which you can hide when building the book. Exporting with Attach Media gives you the most photos WhatsApp will provide; iMazing's export usually includes far more.

I'm on Windows and my iMessage photos won't import.

iMessage photos are typically in Apple's HEIC format, which the Windows version can't decode (they work fine on a Mac). Turn on iMazing's "Convert HEIC to JPEG" option when you export and every photo will come across as a normal JPEG.