How to download large files on a Mac

Before you start: space and drive format

Free space. Open System Settings › General › Storage (on macOS 12 or earlier: Apple menu › About This Mac › Storage) and check you have more room than the file needs. If it’s an archive (.zip, .dmg, .iso) you’ll unpack or install, leave room for the file and what’s inside it.

The drive’s format. Saving to an external drive? Select it in Finder, choose File › Get Info and look at Format. MS-DOS (FAT) is FAT32, which can’t store a file larger than 4 GB. The download fails near the end, or can’t be saved at all. Use a drive formatted as APFS or Mac OS Extended (Mac only) or exFAT (Mac and PC). Reformatting in Disk Utility erases the drive.

Safari unpacks archives for you. With Open “safe” files after downloading turned on in Safari › Settings › General, Safari unzips a finished .zip automatically, so a big archive briefly needs room for two copies. Turn it off if space is tight.

Keep the Mac awake

A sleeping Mac stops downloading. For anything that takes more than a few minutes:

• Plug in and keep the lid open. Closing a MacBook’s lid puts it to sleep unless it’s connected to an external display and power.
• Stop idle sleep for the length of the download. Open Terminal and run caffeinate -i. The Mac stays awake until you press Control-C or close the window.
• Or change the setting. On a MacBook with macOS 13 or later, System Settings › Battery › Options has Prevent automatic sleeping on power adapter when the display is off.

Give it a steady connection

A cable beats Wi-Fi for multi-gigabyte files. If you’re on Wi-Fi, sit close to the router. While it runs, pause other big transfers on the same network (cloud backups, system and game updates, other downloads), and avoid starting a big download just before a video call.

Resume a download that stopped

In Safari

Click the Show Downloads button (the arrow near the top-right of the Safari window) and click the Resume button next to the download. While it’s unfinished, the download sits in your Downloads folder as a file ending in .download. Don’t move or rename it. If the item has disappeared from the list, double-clicking that file usually hands it back to Safari. More in Safari can’t resume this download?

In Chrome

Open chrome://downloads. If the download shows an error such as “Failed – Network error”, click Resume when it’s offered; Chrome also retries some downloads by itself. The unfinished part is saved in your Downloads folder as a .crdownload file. Leave it where it is.

Why resuming sometimes starts from zero

• The server doesn’t allow it. Resuming means asking for “the rest of the file from byte X”, and servers don’t have to support that. If they don’t, every retry starts over.
• The file changed on the server since you started, so the part you have no longer fits.
• The link expired. Many download links are signed and only work for a limited time. Go back to the page and start from a fresh link.
• The partial file was moved, renamed or deleted.

Resume from Terminal with curl

If you have the direct link, curl, which is built into macOS, can download it and pick up after a drop. In Terminal:

cd ~/Downloads
curl -L -O -C - "https://example.com/big-file.iso"

-O keeps the server’s file name, -L follows redirects, and -C - continues from however much of the file is already there. If the connection drops, run the same line again. (It only works if the server allows resuming.)

Check the file when it’s done

Many publishers list a SHA-256 checksum next to big downloads. Most Linux images and developer tools do. In Terminal, type shasum -a 256 (with a space), drag the downloaded file into the window and press Return:

shasum -a 256 ~/Downloads/big-file.iso

Compare the long string it prints with the published one. If they match, your file is exactly what was released. If not, delete it and download it again. (For an older MD5 checksum, use md5 instead.)

When a download manager helps

If you download big files often (disk images, project archives, datasets, installers), a download manager handles the recovery for you:

• It splits a file into parts and fetches them over several connections at once. That helps when a server limits how fast each connection can go. It can’t beat your own internet speed.
• It resumes after a dropped connection, a sleep or a quit, as long as the server allows it. You don’t have to find the partial file.
• It queues the rest while one runs, so ten big files don’t fight each other.

Lynx, our download manager for Mac, splits each file across up to 32 connections and picks up where it stopped when the connection drops. With its browser extension, downloads in Chrome, Edge, Brave and Arc open in Lynx. From Safari, copy the download link and Lynx offers it when you switch to the app. The free version runs 3 downloads at a time; Pro runs up to 10.

Other good options, free and paid, are in the best download managers for Mac.