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quiczquiczquicz

Feature comparison

Updated 2026-07-24. Sources: project READMEs, source code inspection, RFC compliance tracking. Mirrors the authoritative transport task matrix.

Feature RFC quic-go quiche s2n-quic quicz Gap
QUIC v1 transport 9000 ✅ ✅ ✅ ✅ —
QUIC v2 9369 ✅ ❌ ❌ ✅ quiche/s2n-quic only V1
TLS 1.3 9001 ✅(Go crypto/tls) ✅(BoringSSL) ✅(s2n-tls/rustls) ✅(pure Zig) —
0-RTT (early data) 9001 ✅ ✅ ✅ ✅ —
Loss detection & recovery 9002 ✅ ✅ ✅ ✅ —
Connection migration 9000 ✅ ✅ ✅ ✅ —
Path validation 9000 ✅ ✅ ✅ ✅ —
Retry + address validation 9000 ✅ ✅ ✅ ✅ —
Stateless reset 9000 ✅ ✅ ✅ ✅ —
Key update 9001 ✅ ✅ ✅ ✅ —
Version negotiation 9368 ✅ ✅ ✅ ✅ —
DATAGRAM extension 9221 ✅ ✅ ✅(unstable) ✅ —
Multipath draft ✅ ❌ ❌ ✅ —
ECN 9000 ✅ ⚠️ rx only ✅ ✅ quiche does not send ECN
PMTU discovery 8899 ✅ ✅ ✅ ✅ —
GSO/GRO — ✅ ❌ ✅ ✅ quiche defers to app-layer I/O
Connection pool — ✅ ❌ ❌ ✅ —
qlog draft ✅ ✅(feature-gated) ❌(event subscriber) ✅ —
Fuzz targets — ✅(OSS-Fuzz) ✅ ✅ ✅ —
NewReno 9002 ✅ ✅ ❌ ✅ s2n-quic only CUBIC+BBR
CUBIC 9438 ✅ ✅ ✅ ✅ —
BBR — ✅ ✅ ✅ ✅ —
Packet pacing 9002 ✅ ✅ ✅ ✅ —
AES-128-GCM 9001 ✅ ✅ ✅ ✅ —
AES-256-GCM 9001 ✅ ✅ ✅ ✅ —
ChaCha20-Poly1305 9001 ✅ ✅ ✅ ✅ —
X25519 ECDH 8446 ✅ ✅ ✅ ✅ —
X25519Kyber768 (PQ) draft ✅ ✅ ✅ ✅ —
HTTP/3 9114 ✅ ✅ ❌ ⚠️ basic connection management TODO
QPACK static table 9204 ✅ ✅ ❌ ✅ —
QPACK dynamic table 9204 ✅ ✅ ❌ ❌ 2/3 recommended
HTTP Datagrams 9297 ✅ ❌ ❌ ❌ 1/3 optional
WebTransport draft ✅ ❌ ❌ ⚠️ basic session management TODO
Stream reset partial delivery draft ✅ ❌ ❌ ❌ quic-go only
External interop — — — — ✅ all three —
Pure-language TLS (no C) — ✅ ❌ ❌ ✅ —
FIPS 140-3 — ✅(Go 1.26+) ❌ ❌ ❌ quic-go only
XDP zero-copy I/O — ❌ ❌ ✅(unstable) ❌ s2n-quic only

Coverage summary

Section titled “Coverage summary”
Metric quic-go quiche s2n-quic quicz
Transport (19 items) 19/19 14/19 14/19 19/19
Congestion (4 items) 4/4 4/4 3/4 4/4
Cipher suites (5 items) 5/5 5/5 5/5 5/5
Application layer (6 items) 6/6 3/6 0/6 2/6
Platform (3 items) 2/3 0/3 1/3 1/3
Total (37 items) 36/37 26/37 23/37 31/37

Gap analysis

Section titled “Gap analysis”

Mandatory gaps (all three have) — ALL CLOSED:

  1. AES-256-GCM — DONE (675e7ca)
  2. X25519Kyber768 — DONE (675e7ca)

Recommended (2/3 have):

  1. QPACK dynamic table — quic-go + quiche
  2. Complete HTTP/3 connection management — GOAWAY, SETTINGS, stream lifecycle

Optional (1/3 or fewer):

  1. HTTP Datagrams (RFC 9297) — quic-go only
  2. Complete WebTransport session — quic-go only
  3. Stream reset partial delivery — quic-go only (draft)
  4. FIPS 140-3 — quic-go only
  5. XDP zero-copy I/O — s2n-quic only