Absolute locktime uses a strict comparison
Values below 500,000,000 represent block height; higher values represent Unix time. Since BIP113, time locks compare against the previous block’s median time-past, not your wall clock.
Tools · Privacy-first
Timelock & Sequence Decoder
Translate Bitcoin transaction nLockTime and input nSequence fields into absolute and relative lock semantics. The decoder explains BIP68 block/time delays, opt-in RBF signalling, and optional CHECKLOCKTIMEVERIFY or CHECKSEQUENCEVERIFY field comparisons.
This is a field-level learning and review tool. It does not inspect prevouts, execute scripts, validate signatures, read chain state, or prove that a transaction is valid, final, relayable, or spendable.
Runs locally
Your transaction fields stay in this browser.
Local input: Transaction version, nLockTime, input sequence values, optional CLTV/CSV operands, and the input index used for script comparison. Network effect: None when decoding. Values are processed in this page and are not sent to BitcoinStats, a node, an explorer, analytics, browser storage, or the URL.
Lock fieldsBrowser decoderCompatibility report
After the page assets load, decoding works offline. Inputs are not added to the URL, browser storage, analytics, or a server request.
Local input
Describe the transaction fields
Enter unsigned 32-bit fields as decimal or 0x-prefixed hexadecimal. Sequence values may be separated by spaces, commas, semicolons, or new lines. Optional script operands use non-negative Bitcoin Script numbers.
Nothing is uploaded. Decoding starts only when you press “Decode locally”.
Decode result
Lock and sequence summary
Absolute lock
nLockTime interpretation
Review signals
Warnings and limits
Per-input decode
Sequence fields
Optional script context
CLTV and CSV field comparisons
These checks compare the supplied operand with the selected transaction fields. They do not execute the complete script or establish current chain validity.
Purpose and limits
Read the fields without overclaiming the result
BIP68 is relative to each prevout
Version 2 or later and a clear disable bit activate the low 16 sequence bits. Bit 22 selects 512-second units instead of blocks. Actual maturity still needs prevout confirmation data.
CLTV and CSV are script checks
A matching operand is only one condition in a spending path. Signatures, the full script, prevouts, consensus flags, mempool policy, and chain state remain outside this decoder.
Semantics follow BIP65 (CLTV), BIP68 (relative locktime), BIP112 (CSV), BIP113 (median time-past), and BIP125 (opt-in RBF).