Can I mine Monero on an old Android phone I no longer use?

Yes, you can mine Monero on some old Android phones, but it is usually a learning project rather than a useful way to earn money. Your phone’s hardware, Android version, and battery condition matter—and keeping an aging phone hot and plugged in can be a bigger concern than its electricity bill.

Will your old phone actually work?

Monero uses RandomX, a mining algorithm—the set of calculations that miners run to help secure the network. It favors CPUs, the general-purpose processors inside computers and phones, but that does not make every Android phone a good fit.

You generally want a phone with a 64-bit processor and a 64-bit Android system. Some older phones have the right processor but run 32-bit software, which can rule out common mining tools.

Memory is another hurdle:

• RandomX’s fast mode uses a dataset of about 2,080 MB, plus additional memory.
• Its light mode uses a 256 MB cache, but runs much more slowly.
• For efficient mining, allow roughly 2 MB of L3 cache per mining thread. This is fast memory inside the processor; many older phone processors have little or none.

A phone with only 2 GB of RAM—the memory used by running apps—is therefore a poor candidate for fast mode. Having more memory does not guarantee good performance.

Browser mining is not the same as a native miner

A native miner is software that runs directly on your phone, often through a terminal app, which lets you enter text commands. Android setup can require technical work, and not every mining program supports it.

A browser miner runs inside a web page. It may be easier to try, but browser limits, memory demands, and Android’s background restrictions can make it slow or unreliable. Mining may stop when the screen locks or you switch apps.

Also, a website promising XMR payouts is not necessarily mining Monero directly. It could mine something else and pay you in XMR. Check what work your phone performs, the fees, and the minimum withdrawal before leaving it running.

Check the battery before doing anything

An unused phone may already have a worn battery. Mining keeps the processor busy, creating sustained heat; charging adds more.

Before testing:

• Do not use a phone with a swollen battery, a lifting screen, or a separating case. Arrange proper battery service or recycling.
• Put the phone on a hard, uncovered surface, away from sunlight and flammable materials.
• Start with the lowest processing setting and a short, supervised test.
• Stop if it becomes unusually hot, smells odd, restarts, or shows charging problems.

Do not bypass temperature protections or assume an old phone is safe to run unattended just because you no longer need it.

Expect tiny rewards and watch for scams

Your phone’s hashrate, or calculations per second, will likely be very low. Heat can also make it slow itself down automatically.

Use your measured hashrate, electricity cost, and a live mining calculator to estimate returns. Check withdrawal thresholds: a tiny balance may take a very long time to become withdrawable.

Avoid unknown mining APKs—Android installation files—and services demanding payment to “unlock” earnings. A miner needs your public receiving address, not your wallet’s secret recovery words.

The bottom line

You can try mining on a compatible, healthy old Android phone for curiosity. Keep the test supervised and expectations low; for most old phones, the heat, setup effort, and battery wear outweigh the likely rewards.