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Version guide

MultiBit Classic: the complete guide

The original MultiBit wallet (2011–2017). Here's how it stores keys, where its files live, and how to export what you need.

The short answer

MultiBit Classic (2011–2017) is the original MultiBit wallet: a non-deterministic wallet that stores individual private keys in a .wallet file, with optional .key exports. Funds are accessed by exporting or decrypting those keys into a modern wallet like Electrum.

What is MultiBit Classic?

MultiBit Classic was the wallet that introduced many early users to self-custody. Built on Java and bitcoinj, it synced quickly using SPV and ran on Windows, macOS and Linux. It was recommended on bitcoin.org and, by 2013, managed roughly 1.5 million Bitcoin addresses.

Its defining technical trait is that it is non-deterministic. Each address MultiBit Classic generated had its own private key, stored independently. There is no single seed that reproduces the wallet — which is why backup discipline was critical, and why recovery means working with the keys directly.

How MultiBit Classic stores your keys

The wallet uses two file types you need to know about:

  • .wallet — the main wallet file, serialized with bitcoinj's protobuf format. It contains your private keys (encrypted or unencrypted) and transaction history.
  • .key — a separate export of one or more private keys, either in plain text or AES-encrypted. These are created via Tools → Export Private Keys.
  • .info — a small metadata sidecar file that sits next to the .wallet file.

MultiBit Classic also maintains automatic backups in a <walletname>-data/ folder, including wallet-backup/ and key-backup/ snapshots — worth checking if your main files are missing.

Where MultiBit Classic stores its files

Files live in an operating-system-specific MultiBit folder. The exact paths matter if you are searching an old computer or backup drive:

Operating systemDefault folder
Windows%APPDATA%\MultiBit\
macOS~/Library/Application Support/MultiBit/
Linux~/MultiBit/

MultiBit Classic not opening?

If MultiBit Classic won't open, crashes on launch or hangs on “Synchronising…”, a launch failure alone does not mean the bitcoin has been lost — the wallet file is separate from the app. These problems are usually a Java, file or sync issue with clear fixes: rename the spvchain file (add .disabled), check your Java installation, and open the wallet from the correct folder. The won't open guide walks through every fix step by step.

How to export MultiBit Classic private keys

  1. Open your wallet in a MultiBit Classic client (or use a key extractor if it is password-protected).
  2. Go to Tools → Export Private Keys and export to a .key file.
  3. Keep the file safe — anyone with it can spend your bitcoin.
  4. In Electrum, create a new standard wallet with a freshly generated seed, open Wallet → Private Keys → Sweep, and paste the keys. This moves the funds directly into the new wallet and retires the old keys.

Full instructions with screenshots-level detail are in our export private keys guide and move to Electrum guide.

MultiBit Classic vs MultiBit HD — in one glance

  • Classic: individual keys in .wallet/.key, no seed phrase.
  • HD: 12-, 18- or 24-word seed phrase, data in mbhd.wallet.aes.

If you have a seed phrase you have HD; if you have .wallet / .key files and no seed words, you have Classic. Full comparison: Classic vs HD guide.

Next steps for Classic users

Export private keys
Step-by-step extraction from .wallet and .key files.
Learn more
Move to Electrum
Sweep your keys into a new standard wallet.
Learn more
Download Classic safely
Only preserved original release records.
Learn more
Classic vs HD
Make sure you have the right wallet.
Learn more
Forgot password?
Recover access to a password-protected wallet.
Learn more

MultiBit Classic FAQ

Is MultiBit Classic safe to use in 2026?

No. MultiBit Classic was discontinued in July 2017, receives no security updates, and struggles to synchronize with the Bitcoin network. It should only be opened long enough to export your private keys, which you then move to a modern wallet such as Electrum.

Does MultiBit Classic have a seed phrase?

No. MultiBit Classic is a non-deterministic wallet: it generates a collection of individual private keys stored in a .wallet file, with optional .key exports. There is no seed phrase in Classic — you recover by exporting or decrypting the keys themselves.

Which files make up a MultiBit Classic wallet?

The main file is the .wallet file (bitcoinj protobuf format) holding your private keys and history, next to a small .info sidecar. Exported keys live in .key files, and automatic backups sit in a walletname-data folder with wallet-backup and key-backup snapshots.

What if my Classic .wallet or .key file is encrypted?

If you have an unencrypted .key export, you can import those keys directly. If the .wallet or .key file is encrypted and the password is lost, decryption of the file itself is required; the more you remember about the password, the better the chances.

How long does it take to move funds out of MultiBit Classic?

Exporting the keys takes minutes (Tools → Export Private Keys). The time-consuming part is sweeping them into a modern wallet like Electrum and waiting for it to scan the blockchain for your balances — usually a few minutes for a handful of addresses.

MultiBit Classic won't open — is my bitcoin lost?

Not by itself. The .wallet file is separate from the application, so a launch failure alone does not mean the bitcoin has been lost — your keys remain in that file. Most launch problems are Java- or sync-related and fixable — see the won't-open guide for the step-by-step fix, then verify your known receiving addresses on an independent block explorer.

I forgot my MultiBit Classic password — can I still get my bitcoin?

Usually yes. If you ever exported an unencrypted .key file (Tools → Export Private Keys), those keys import directly into Electrum with no password. If only an encrypted .wallet file remains with no key export, the keys inside are locked by the password — recovery means remembering it or running an offline search with btcrecover/mbtcrecover. See the forgot-password guide for the full breakdown.

I found an old MultiBit wallet file — where is it stored and what do I do with it?

On Windows, Classic stored its data under %APPDATA%MultiBit; on macOS in ~/Library/Application Support/MultiBit; on Linux in ~/MultiBit. Look for .wallet, .key and .info files plus a walletname-data folder with wallet-backup and key-backup copies. The .wallet file holds your private keys — start with the Classic key-export guide to recover them.

How do I open a .wallet or .key file?

A .wallet file is a bitcoinj protobuf wallet file — you open it inside MultiBit Classic itself, or extract the keys with a carefully vetted open-source tool (verify its source and hashes, run it offline) if you no longer have the app. A .key file is an exported key file: unencrypted .key files open directly in Electrum (Wallet → Private Keys → Sweep), while encrypted ones need the password or a reviewed key-extraction tool.

What are the wallet-backup and key-backup folders in my MultiBit data folder?

They are automatic backups MultiBit Classic made while the wallet was in use. The wallet-backup folder holds timestamped copies of your .wallet file, and key-backup holds copies of your exported .key files. If your main wallet file is missing, corrupted or deleted, check these folders first — they often contain a working copy of your keys.
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