PCAP Viewer | Open PCAP and PCAPNG Online

PCAP viewer that opens .pcap and .pcapng captures in your browser. Decodes TCP, UDP, DNS, HTTP and TLS, with Wireshark-style filters. Never uploaded. Free. Designed specifically for developers and professionals, this free online networking runs entirely in your browser to process tasks quickly and securely. Enjoy unlimited usage with no data tracking and no registration required.

Also known as: pcap viewer · pcap viewer online · pcap analyzer online · open pcap file online · pcapng viewer online · pcap file reader · wireshark online · open pcap file without wireshark · pcap to csv · pcap dns analyzer

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ssl and security tools

networking

Capture File

Drop a .pcap or .pcapng file here, or click to browse

Read locally with the File API in 16 MB blocks, so multi-gigabyte captures work. Nothing is uploaded.

Packets

Wireshark-style filters: tcp, udp, dns, http, tls, arp, ip.addr == 10.0.0.5, tcp.port == 443, tcp.flags.syn == 1, frame.len > 1000, combined with && || ! and parentheses.

Open a .pcap or .pcapng file, or load the example, and every packet will be listed here with its source, destination, protocol and a Wireshark-style info column.

About PCAP Viewer

A PCAP viewer is used to open packet captures from tcpdump, Wireshark or a cloud traffic mirror and read them without installing anything. This one streams .pcap and .pcapng files from disk in your browser, lists every packet with a Wireshark-style info column, decodes DNS, HTTP, TLS and TCP, and summarizes conversations and protocols, so you can triage even a multi-gigabyte capture on a laptop without Wireshark.

Key Features

Streams captures of any size from disk in 16 MB reads and keeps a compact index, so multi-gigabyte files open and the first page appears while the rest is indexed
Reads classic pcap (microsecond or nanosecond, either byte order), pcapng with multiple interfaces, and gzip-compressed .pcap.gz files
Decodes Ethernet, VLAN, Linux cooked capture, IPv4, IPv6, TCP, UDP, ICMP, ARP, DNS, HTTP, TLS with SNI and ALPN, DHCP and QUIC, and unwraps VXLAN, GENEVE and ERSPAN
Wireshark-style display filters such as tcp.port == 443, dns, ip.addr == 10.0.0.0/8 and !arp scan the whole capture in the background, with a live match count
Conversation and protocol hierarchy tables, plus a layer-by-layer breakdown and a hex dump of any packet you click
Streams the full or filtered packet list to a CSV or JSON download, with progress and a cancel button

Use Cases

Open a capture attached to a help desk ticket on a laptop that does not have Wireshark installed
Read a multi-gigabyte tcpdump or AWS VPC Traffic Mirroring capture from an EC2 host without loading it into memory
Check which SNI and ALPN a client sends in its TLS Client Hello when a load balancer serves the wrong certificate
Find slow or failing DNS lookups, such as NXDOMAIN responses for an internal api.corp.example.com name
See which side sent a TCP reset before you escalate a firewall or security group ticket
Turn a capture into a CSV of packets for a postmortem document or a SOC 2 evidence folder

Supported Formats

.pcap

.pcapng

.cap

.pcap.gz

Ethernet

Linux cooked (SLL, SLL2)

Raw IP

BSD loopback

Related Keywords

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How do I open a PCAP file without Wireshark?

Drop the .pcap or .pcapng file on this page. The viewer reads it with the browser's File API in large blocks and decodes packets on your machine, so nothing is uploaded and even multi-gigabyte captures stay out of memory. That matters more for captures than for most files: an unencrypted capture can hold session cookies, Authorization headers, API keys and passwords sent over FTP or Telnet. For deep work such as TCP stream reassembly, expert analysis or decrypting TLS with a key log file, Wireshark or tshark is still the right tool; this viewer is built for a fast first look.

Privacy & Security

All processing happens locally in your browser. Your data never leaves your computer, ensuring complete privacy and security.

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Frequently asked questions

What is PCAP Viewer used for?

PCAP viewer that opens .pcap and .pcapng captures in your browser. Decodes TCP, UDP, DNS, HTTP and TLS, with Wireshark-style filters. Never uploaded. Free.

Is PCAP Viewer free to use?

Yes. PCAP Viewer is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use PCAP Viewer?

No. PCAP Viewer works immediately in your browser with no signup, login, or email address required.

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