How to Reduce Photo Size on iPhone

The iPhone can shrink photos only to fixed sizes: Mail offers Small, Medium and Large when you send them. File Acture's Compress Images brings each photo under a size you type, such as 500 KB, by finding the highest quality that fits, and does a whole batch on the iPhone without uploading anything.

Updated October 31, 20264 min read

By the File Acture team

A visa form that accepts photos up to 500 KB, a listing site that rejects anything over 2 MB, a chat app that keeps failing to send: an iPhone photo of 3–5 MB is often too big. Here is what the iPhone can do on its own and how to get a batch of photos under an exact size.

Why are iPhone photos so large?

A photo from a recent iPhone has 12 to 48 million pixels saved at high quality, far more than a web form or an email needs. The file size depends on how many pixels there are and how strongly they are compressed.

Lowering the quality a little shrinks a photo a lot with little visible change; reducing the pixel size shrinks it further. A tool that aims at a size has to balance the two for every photo.

How to make photos smaller without an app

When you send photos in Mail, the iPhone offers to reduce them: Small, Medium, Large or Actual Size. It is quick for an email, but you choose a size class, not a file size, and the smaller photos only exist inside that message.

In Settings › Camera › Formats, High Efficiency (HEIC) already keeps new photos about half the size of JPG. Many forms do not accept HEIC, though, so it rarely solves an upload problem.

How to compress photos to a target size with File Acture

Open Compress Images and tap Add from Photos, or Add from Files for images saved in Files. Under Size, choose Target size and type a value in KB or MB, or pick 100 KB, 250 KB, 500 KB, 1 MB or 2 MB from Presets.

File Acture starts at a high quality and steps down until each photo fits. If even a low quality is too big, it scales the photo down in steps, so a very small target also reduces the pixel size. When a target is out of reach, it tells you the smallest size it could make.

Tap Compress. Each photo is saved with “-compressed” in its name in On My iPhone › File Acture › Images, and Share All sends the whole batch at once.

Compress by quality instead

With no size limit, choose Quality under Size and set the slider. Every photo gets the same quality, which keeps a batch looking consistent.

Which format gives the smallest photos?

Format decides what the compressed photos are saved as.

Keep original: each photo stays in its own format, so HEIC stays HEIC.
JPEG: the safe choice for any upload form. If a form asks for JPG, choose this.
WebP: usually the smallest, for websites that accept it.
Metadata: Keep metadata is off by default, so location and camera details are removed.

Is it safe to compress photos online?

An online compressor receives your photos, often with the location inside them. File Acture compresses on the iPhone; the free version handles up to 5 photos per run, 5 runs a day, and Pro removes the limits. If you also need JPG files from HEIC, convert them first or simply choose JPEG here.