[1.61.3] - 2026-05-09
- ADDED: Custom payload for UDP fake packets - new "Fake Packet Payload" picker in the UDP fake settings of each set. Choose a captured
.bin(uploaded in Settings → Payloads, or auto-captured from live QUIC traffic) to use as the body of fake UDP packets. Empty = zero fill (previous behavior). The Settings → Payloads upload form now has an explicit TLS/QUIC protocol selector. - ADDED: Auto-generated QUIC Initial payload - new "(auto: QUIC Initial)" option in the UDP Fake Packet Payload picker. b4 generates a fresh randomized QUIC Initial packet for every fake, with random connection IDs each time, so no upload is needed and the bytes can't be fingerprinted by repetition. Recommended packet size for this mode is 1200 bytes. Works with any Faking Strategy (None / TTL / Checksum).
- ADDED: Bundled QUIC presets - two ready-to-try options ("QUIC preset 1" and "QUIC preset 2") in the UDP Fake Packet Payload picker. Pick one if the auto option does not work for your provider; if neither helps, upload your own
.bin. - ADDED: MTProto relay setup helper — new "?" button next to the DC Relay field in Settings → MTProto Proxy. Opens a popup with the current Telegram data center list and ready-to-copy commands for the VPS, so nothing has to be calculated or guessed by hand.
- ADDED: Single-instance enforcement — b4 now refuses to start if another b4 process is already running on the same host, exiting with a clear message and the existing PID.
- ADDED: Sequence overlap length for fragmentation - new "Overlap Length" field for Combo and Disorder splitting. b4 prepends the configured number of pattern bytes to one of the real fragments with its TCP sequence number shifted back by the same amount, in addition to (or instead of) the existing fake-packet overlap.
- ADDED: AI field explanations (experimental) - small AI buttons next to some fields open a popup that explains what the field does. Work in progress: only a few fields are covered and answers can be wrong or incomplete. Not recommended to rely on yet.
- IMPROVED: Web UI error messages - when saving a configuration or a set fails, the Web UI now shows a clear reason (for example, a port is already in use).
- FIXED: Upstream SOCKS5 routing failed on BusyBox routers — sets routed through an upstream SOCKS5 proxy were missed by the 1.49.0 fix and still hit the
BusyBoxtable-ID limit. Now kept within the safe range too. - FIXED: QUIC blocking sometimes does not work for YouTube on phones - newer Chrome versions on Android use a QUIC variant b4 didn't recognize, so "block all QUIC" let those packets through and YouTube kept working in the browser. b4 now recognizes any QUIC packet, current or future.
- FIXED: Routing fails on MikroTik containers when interface names contain dashes - interface names with dashes were rejected by
nft. b4 now quotes interface names in routing rules, so any name works. - FIXED: Interface routing did not work on MikroTik container bridges - when several container interfaces shared one bridge with a single upstream gateway, the per-set default route was added without a gateway and traffic went nowhere. b4 now reuses the system gateway when it is reachable through the chosen interface.
- FIXED: Backup file could not be selected in Safari on macOS - the file picker greyed out the downloaded
.tar.gzbackup file. Selecting the backup now works in Safari. - FIXED: Voice calls, screen share and gaming could break in UDP fake mode - b4 was splitting all matched UDP packets, which could disrupt voice, screen share and gaming traffic. Only QUIC packets are split now; the rest pass through untouched.
What's Changed
- fix: update routing logic to handle default gateways and interface re… by @DanielLavrushin in #219
Full Changelog: v1.61.2...v1.61.3