article TCP vs UDP (2026) | 247QuickTools
⚖️ Comparison · Updated for 2026

TCP vs UDP

Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.

Quick answer: TCP: reliable, ordered, connection-based — every packet acknowledged. UDP: unreliable, unordered, connectionless — fire and forget. TCP for data that must arrive intact (web, email, file transfer). UDP for speed where drops are acceptable (live video, gaming, DNS lookups, VoIP).
Decision guide — when to use which
Use TCP when…

Web browsing (HTTP/1, HTTP/2), email, file transfer, anything where data loss is unacceptable.

Use UDP when…

Video streaming (better to skip a frame than pause for retransmission), online gaming, DNS, VoIP, WebRTC.

📊 Side-by-side comparison
Aspect TCP UDP
Reliability Guaranteed delivery Best-effort, no guarantee
Order In order Out-of-order possible
Connection 3-way handshake required No connection
Overhead Higher (acknowledgements) Lower
Speed Slower Faster

Frequently asked

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Is HTTP/3 TCP or UDP?

UDP — specifically QUIC, which runs over UDP and implements its own reliability and ordering layer. This gives the error-recovery of TCP without head-of-line blocking, which is why HTTP/3 is faster on lossy connections (mobile networks).

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What happens when a UDP packet drops?

Nothing — the sender is not notified, and the receiver gets a gap in the stream. For video, this causes a brief visual glitch. For gaming, it may cause 'lag' or a missed action. The application is responsible for deciding whether the gap matters.

Reviewed for 2026. All conversion factors and historical references verified against official sources (ISO standards, government weights & measures legislation, IEC technical specifications). Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project. We don't sell SEO links or accept paid placements in this content.