⚖️ 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. This comparison is general guidance based on publicly available information. Prices, rates, rules and specifications change, so check current details with the provider or an official source before making a decision. 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.

Frequently asked questions

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).

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.