Inspect FlatBuffers root tables: optional size prefix, root offset, vtable sizes, and per-field offsets/scalars as JSON.
Privacy: Decoding runs entirely in this tab. Your bytes and optional schema text are not uploaded to Codeground servers.
Binary payload
Decoded output
{
"sizePrefixed": false,
"bufferLength": 20,
"rootOffset": 12,
"tablePosition": 12,
"vtablePosition": 4,
"vtableSize": 6,
"objectSize": 8,
"fields": [
{
"index": 0,
"present": true,
"fieldOffset": 4,
"absoluteOffset": 16,
"asInt32": 42,
"asUint32": 42,
"rawHex": "2a 00 00 00"
}
]
}Without a schema, FlatBuffers still expose vtable layout. This tool dumps structural metadata so you can debug offsets and scalar fields from a binary capture.
Paste Base64, hex, or PEM (for ASN.1). Auto-detect treats even-length hex strings as hex; otherwise Base64 is assumed. Whitespace is stripped automatically.
Do you upload my binary payloads? No. Decoding runs entirely in your browser. Bytes and optional schemas never leave this tab.
Do I need a .fbs schema? Not for this structural dump. Field names require a schema-aware tool; here you see indexes and values.
Size-prefixed buffers? Detected automatically when the first uint32 matches the remaining length.
What input formats work? Base64 or hex FlatBuffers binaries.
Related: Protobuf decoder · MessagePack · CBOR · Base64 decode · JSON formatter