Bitcoin Core file system


Data directory location

The data directory is the default location where the Bitcoin Core files are stored.

  1. The default data directory paths for supported platforms are:
Platform Data directory path
Linux $HOME/.bitcoin/
macOS $HOME/Library/Application Support/Bitcoin/
Windows %APPDATA%\Bitcoin\ [1]
  1. A custom data directory path can be specified with the -datadir option.

  2. All content of the data directory, except for bitcoin.conf file, is chain-specific. This means the actual data directory paths for non-mainnet cases differ:

Chain option Data directory path
-chain=main (default) path_to_datadir/
-chain=test or -testnet path_to_datadir/testnet3/
-chain=signet or -signet path_to_datadir/signet/
-chain=regtest or -regtest path_to_datadir/regtest/

Data directory layout

Subdirectory File(s) Description
blocks/ Blocks directory; can be specified by -blocksdir option (except for blocks/index/)
blocks/index/ LevelDB database Block index; -blocksdir option does not affect this path
blocks/ blkNNNNN.dat[2] Actual Bitcoin blocks (in network format, dumped in raw on disk, 128 MiB per file)
blocks/ revNNNNN.dat[2] Block undo data (custom format)
chainstate/ LevelDB database Blockchain state (a compact representation of all currently unspent transaction outputs (UTXOs) and metadata about the transactions they are from)
indexes/txindex/ LevelDB database Transaction index; optional, used if -txindex=1
indexes/blockfilter/basic/db/ LevelDB database Blockfilter index LevelDB database for the basic filtertype; optional, used if -blockfilterindex=basic
indexes/blockfilter/basic/ fltrNNNNN.dat[2] Blockfilter index filters for the basic filtertype; optional, used if -blockfilterindex=basic
wallets/ Contains wallets; can be specified by -walletdir option; if wallets/ subdirectory does not exist, wallets reside in the data directory
./ anchors.dat Anchor IP address database, created on shutdown and deleted at startup. Anchors are last known outgoing block-relay-only peers that are tried to re-connect to on startup
./ banlist.dat Stores the IPs/subnets of banned nodes
./ bitcoin.conf User-defined configuration settings for bitcoind or bitcoin-qt. File is not written to by the software and must be created manually. Path can be specified by -conf option
./ Stores the process ID (PID) of bitcoind or bitcoin-qt while running; created at start and deleted on shutdown; can be specified by -pid option
./ debug.log Contains debug information and general logging generated by bitcoind or bitcoin-qt; can be specified by -debuglogfile option
./ fee_estimates.dat Stores statistics used to estimate minimum transaction fees and priorities required for confirmation
./ guisettings.ini.bak Backup of former GUI settings after -resetguisettings option is used
./ IP addresses to Autonomous System Numbers (ASNs) mapping used for bucketing of the peers; path can be specified with the -asmap option
./ mempool.dat Dump of the mempool's transactions
./ onion_v3_private_key Cached Tor onion service private key for -listenonion option
./ peers.dat Peer IP address database (custom format)
./ settings.json Read-write settings set through GUI or RPC interfaces, augmenting manual settings from bitcoin.conf. File is created automatically if read-write settings storage is not disabled with -nosettings option. Path can be specified with -settings option
./ .cookie Session RPC authentication cookie; if used, created at start and deleted on shutdown; can be specified by -rpccookiefile option
./ .lock Data directory lock file

Multi-wallet environment

Wallets are Berkeley DB (BDB) or SQLite databases.

  1. Each user-defined wallet named "wallet_name" resides in the wallets/wallet_name/ subdirectory.

  2. The default (unnamed) wallet resides in wallets/ subdirectory; if the latter does not exist, the wallet resides in the data directory.

  3. A wallet database path can be specified with the -wallet option.

  4. wallet.dat files must not be shared across different node instances, as that can result in key-reuse and double-spends due the lack of synchronization between instances.

  5. Any copy or backup of the wallet should be done through a backupwallet call in order to update and lock the wallet, preventing any file corruption caused by updates during the copy.

Berkeley DB database based wallets

Subdirectory File(s) Description
database/ BDB logging files Part of BDB environment; created at start and deleted on shutdown; a user must keep it as safe as personal wallet wallet.dat
./ db.log BDB error file
./ wallet.dat Personal wallet (a BDB database) with keys and transactions
./ .walletlock BDB wallet lock file

SQLite database based wallets

Subdirectory File Description
./ wallet.dat Personal wallet (a SQLite database) with keys and transactions
./ wallet.dat-journal SQLite Rollback Journal file for wallet.dat. Usually created at start and deleted on shutdown. A user must keep it as safe as the wallet.dat file.

GUI settings

bitcoin-qt uses QSettings class; this implies platform-specific locations where application settings are stored.

Legacy subdirectories and files

These subdirectories and files are no longer used by the Bitcoin Core:

Path Description Repository notes
blktree/ Blockchain index; replaced by blocks/index/ in 0.8.0 PR #2231, 8fdc94cc
coins/ Unspent transaction output database; replaced by chainstate/ in 0.8.0 PR #2231, 8fdc94cc
blkindex.dat Blockchain index BDB database; replaced by {chainstate/, blocks/index/, blocks/revNNNNN.dat[2]} in 0.8.0 PR #1677
blk000?.dat Block data (custom format, 2 GiB per file); replaced by blocks/blkNNNNN.dat[2] in 0.8.0 PR #1677
addr.dat Peer IP address BDB database; replaced by peers.dat in 0.7.0 PR #1198, 928d3a01
onion_private_key Cached Tor onion service private key for -listenonion option. Was used for Tor v2 services; replaced by onion_v3_private_key in 0.21.0 PR #19954


1. The / (slash, U+002F) is used as the platform-independent path component separator in this document.

2. NNNNN matches [0-9]{5} regex.