Native Client is a sandboxing technology that allows running a subset of native code (from x86, ARM, or MIPS architectures) safely inside a web browser. A web page could run a NaCl program much like a Flash program, and JavaScript code on that page could interact with the program by passing messages.
Despite its technical merits, the nacl-web-plug-in was officially . The reasons were:
Today, NaCl is remembered as a bold experiment that proved the web could handle heavy applications, paving the way for the modern "standard" (WebAssembly) that we use for everything from online gaming to browser-based video editing today. nacl-web-plug-in
: Google officially deprecated NaCl in 2020, urging developers to migrate to WebAssembly for cross-browser compatibility. Common Uses & Legacy Hardware
Google officially began phasing out Native Client in 2022. By the beginning of 2025, Chrome had removed most NaCl functionality. Google further announced that Native Client would be disabled from ChromeOS 132 onwards (January 2025) and that ChromeOS 138 (July 2025) would be the last version with any NaCl support. Even more significantly, the LLVM compiler stack removed its support for building any new NaCl or PNaCl binaries in LLVM 22, which was finalized in July 2025. This means that even if you manage to run an older version of Chrome, you can no longer compile new NaCl modules – the toolchain itself is gone. Native Client is a sandboxing technology that allows
: The outer layer restricted the process to a narrow "kernel" API. On Linux, this was done using seccomp-bpf , which filtered the system calls the NaCl module could invoke. This defense-in-depth strategy ensured that even if an attacker bypassed the SFI, they would still be contained by the OS-level restrictions.
Which (C++, Rust, Go) does your codebase use? What performance bottlenecks are you trying to solve? The reasons were: Today, NaCl is remembered as
At its peak, the NaCl web plug-in offered several unprecedented advantages for web development:
: Since Google officially deprecated PNaCl (Portable Native Client) in favor of WebAssembly, most modern browsers (Chrome, Edge, Firefox) no longer support these plugins by default. If a firmware update isn't possible, some users resort to using "Internet Explorer mode" in Edge or older versions of Firefox to maintain functionality. Microsoft Learn ⚠️ Security Context Malware Concerns
Developers could port massive legacy desktop applications written in C/C++ to the web without rewriting them in JavaScript.