An important document arrives, you tap the download arrow — and nothing happens. The paperclip spins forever, or Gmail flashes "Couldn't download attachment" and gives up. Small files download fine; the big ones don't. Or nothing downloads at all, on Wi-Fi and data alike.
Attachment downloads fail for a small set of reasons, and they're almost all fixable on the phone: a shaky connection that can't finish the transfer, a full storage that leaves nowhere to save the file, a corrupted app cache, or a Gmail app that's simply out of date. The six fixes below run from the likeliest cause to the last-resort rebuild — and the one that trips most people is storage, so don't skip Fix 1.
Quick Answer
First, check you have free storage (Settings → Storage) — a nearly-full phone is the most common cause. Then go to Settings → Apps → Gmail → Storage → Clear cache, and make sure Gmail has its Files and media / Storage permission under App info → Permissions. Update Gmail from the Play Store too — a stale build breaks downloads quietly. Covers Android 10 through 14.
In This Guide
Fix 1 — Check the Connection and Free Up Storage
Attachments are the heaviest thing Gmail downloads, so they fail first when conditions are marginal. A connection that's fine for text mail can stall on a 20 MB PDF, and a phone with 300 MB free has nowhere to put it. Rule both out before touching anything else.
- Load any webpage in your browser. If pages don't load, that's your problem — switch between Wi-Fi and mobile data and retry the download. Moving closer to the router or waiting out a crowded public network also helps.
- Open Settings → Storage and check free space. If it's under ~1 GB, delete a few large files, clear WhatsApp's forwarded-media pile, or empty the Downloads folder.
- Also confirm your Google account storage isn't the blocker — attachments you save to Drive count against the 15 GB quota. Check it at one.google.com/storage.
- Retry the attachment download after freeing space.
Fix 2 — Clear Gmail's Cache
Corrupted cache is the classic "downloads fail on every file" cause. Gmail stores partial downloads and previews in its cache, and when those entries corrupt, every new download attempt collides with the broken leftovers. Clearing the cache wipes them without touching your mail.
- Go to Settings → Apps → Gmail → Storage.
- Tap Clear cache — not "Clear data," just the cache.
- Force-stop Gmail from the same App info screen, then reopen it.
- Open the email and try the attachment again.
If the attachment still fails, note exactly what happens: a spinner that never ends points at connection or storage; an instant error message points at the file itself or the app. That distinction saves you time on the fixes ahead.
Fix 3 — Grant Gmail Its Storage Permission
Gmail can't save a file it isn't allowed to touch. On many phones the storage permission gets revoked silently — during an update, a permission review, or when you tapped "Don't allow" once and forgot. The app then fails every download without ever asking again.
- Long-press the Gmail icon → App info → Permissions.
- Tap Files and media (on older Android: Storage) and set it to Allow — or Allow only while using the app at minimum.
- Samsung (One UI): also check Settings → Apps → Gmail → Permissions → Storage; Xiaomi (HyperOS): check Settings → Apps → Manage apps → Gmail → App permissions → Storage.
- Retry the download. The first success usually means every download was being blocked by this one permission.
Fix 4 — Update the Gmail App
Google quietly changes how attachments are handled on the server side, and an old Gmail build can fall out of step — downloads fail with no useful error. If the app hasn't updated in a while, this is an easy win.
- Open the Play Store, search Gmail, and tap Update if one is waiting.
- While you're there, confirm your phone's system software is reasonably current (Settings → System → System update) — ancient system builds can break the download pipeline too.
- Restart your phone after the update, then retry the attachment.
If the Play Store itself won't update Gmail, clear the Play Store's cache (Settings → Apps → Google Play Store → Storage → Clear cache) and try the update again.
Fix 5 — Work Around Tricky Attachments
Some attachments are hard to download no matter how healthy the app is: huge files over the 25 MB Gmail limit arrive as Drive links, confidential-mode messages restrict downloading by design, and unusual file types can confuse the app. The workaround is to stop fighting the download and take another path.
- Tap the attachment to preview it first. If it previews, use the Save to Drive option from the preview menu — then open it from Drive.
- For very large attachments, open mail.google.com in Chrome on the phone and download from the desktop-style view — it handles big files more gracefully.
- If the message is in Confidential Mode (a lock icon with a timer), Gmail may intentionally block downloads. Ask the sender to resend it normally.
- For suspicious file types that Gmail refuses to touch, ask the sender to zip the file first.
The Drive-save route is also the answer when the file downloads but won't open — Drive renders most document and image formats without needing any other app.
Fix 6 — Remove and Re-Add Your Google Account
When every attachment fails on every network and nothing above helped, the account's sync session with Google's servers is likely damaged. Removing the account and signing back in rebuilds that session from scratch.
- Go to Settings → Accounts (or Passwords & accounts) and tap your Google account.
- Tap Remove account and confirm. Your emails stay in the cloud — nothing is deleted from your inbox.
- Restart your phone.
- Return to Settings → Accounts → Add account → Google, sign in, open Gmail, and let the first sync finish before testing a download.
Make sure you know the account password before removing it. And if the attachment downloads fine in a browser but never in the app, that's your sign the app state — not your account — is the problem, and Fix 6 is the right finish.
Watch: Gmail Attachments Not Downloading Fixed Step by Step
Prefer a walkthrough? This video covers Gmail attachments not downloading step by step:
Video by How To Fix Pro — full credit to the creator.
Related Guides
Frequently Asked Questions
Why do small Gmail attachments download but big ones fail?
Large files stress every weak link: a flaky connection times out mid-transfer, low storage has nowhere to put the file, and some networks throttle large downloads. Start with Fix 1, and if big files still fail on every network, try downloading them via Chrome at mail.google.com instead of the app.
Can I download attachments over mobile data?
Yes, unless Data Saver or Gmail's data restrictions are blocking it. Check Gmail → App info → Mobile data & Wi-Fi and make sure Background data and Unrestricted data usage are on.
Why does Gmail say "Couldn't preview" before I even try to download?
The preview failed, not the download — they're different steps. It usually means the file type isn't supported by the previewer or the file is very large. Try the Save to Drive option or the direct download arrow; one of them typically works even when the preview doesn't.
By Sameer Zehri | App Fix Guru Editor | Last updated: October 2026
