MailBalance — see what's eating your Google storage
MailBalance is a free tool that reads the size and headers of your Gmail messages and shows you the heaviest emails, senders, labels and years — so you can free up gigabytes in minutes. It runs entirely inside your browser tab.
No account. No install. No payment. First results in under 30 seconds.
What MailBalance does
Google gives you 15 GB shared across Gmail, Drive and Photos. When it fills up, Gmail stops receiving mail — but Gmail itself gives you no breakdown of what is using the space. MailBalance builds that breakdown:
- Overview — how much you could reclaim, right at the top.
- Heavy messages — every email over a size you choose, biggest first.
- Senders — which senders cost you the most storage, in total.
- Labels — weight per label and per Gmail category.
- By year — which years of mail are the expensive ones.
- Cleanup packs — one-tap Gmail searches (big old attachments, Promotions over 1 MB, your top ten senders…) with a live size estimate.
Every row links straight into Gmail search, where you review and delete. MailBalance never deletes, moves or modifies anything in your mailbox.
How it works
- You sign in with Google and grant one read-only scope,
gmail.metadata. Nothing happens before you do. - Your browser asks Gmail for message sizes and headers and adds them up locally. The heaviest mail appears within seconds; the full index keeps building behind it.
- You clean up in Gmail by following the links MailBalance shows you. Re-open it any time — the index is cached on your device, so a re-check is instant.
What data it accesses
MailBalance requests exactly one Google OAuth scope, and no other, ever:
| Scope | What it grants | Why it's needed |
|---|---|---|
gmail.metadata |
Read-only access to email metadata — labels, headers and message size. It does not grant access to message bodies or attachments. | Message size is the entire product. Ranking your heaviest senders, labels and years is impossible without it. |
This is the least permissive scope that can do the job — the broader
gmail.readonly would also work, but it would hand over the full content of
every email, which MailBalance neither needs nor wants. From each message it reads only
the id, the size, the date, the labels and three headers (From,
Subject, Content-Type).
Nowhere. Requests go from your browser straight to Google's servers and the answers
come straight back. The resulting index is written to your browser's own IndexedDB
storage; your access token lives in sessionStorage and disappears when you
close the tab. You can erase everything with "Sign out", or revoke access entirely from
your
Google Account permissions page.
MailBalance's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Full details are in the Privacy Policy.
Questions
Is it really free?
Yes. There is no account, no paid tier and no advertising. There is also no server to pay for — the whole thing is a static page.
Can MailBalance read my emails?
No. The gmail.metadata scope does not grant access to message bodies or
attachments, so the content of your mail is out of reach by design — not merely by
promise.
Will it delete anything?
Never. It has read-only access and no delete capability at all. It shows you what to look at and links you into Gmail, where you decide.
How long does a scan take?
The first actionable results land in seconds. A complete index is bounded by Gmail's API rate limit — roughly 50 messages per second — so a very large mailbox can take a while to finish. You can use the results while it runs, and pause and resume freely.
Does it work on a phone?
The scan does. Cleaning up is easier on a desktop, because Gmail's mobile web app doesn't follow search links properly — MailBalance offers to send itself to your computer when you tap a Gmail link on a phone.
Who makes it?
An independent developer. MailBalance is not affiliated with, sponsored by or endorsed by Google LLC. Questions: contact@mailbalance.emergence.md.
Ready to find your dead weight?
Sign in with Google, and see the number in under 30 seconds.