clcache vs EngFlow Remote Caching

clcache is a free, open-source Python script for Windows builds using Microsoft Visual C++ cl.exe. It intercepts compiler calls and reuses cached object files to avoid recompiling matching work, while unsupported invocations can be passed to the real compiler. Cache keys use preprocessed source, a normalized command line, and the compiler binary’s size and modification time. Command-line controls provide statistics, cleanup, clearing, and maximum-size settings; the default limit is 1073741824 bytes (1 GiB). Object files can be compressed at levels 1 through 9, though changing compression settings requires clearing the cache. Hard-link mode requires cache and build directories on the same drive. Documentation covers Visual Studio and MSBuild integration, recommends disabling TrackFileAccess, and describes optional hash caching and memcached storage. The documented path requires /c, excludes /link and /Zi, and supports /Z7. INCLUDE and LIBPATH changes may not be detected.

EngFlow Remote Caching is a remote cache service for reducing repeated builds and test reruns, developer workload, and compute costs. It uses gRPC, cache compression, and Build without the Bytes to limit latency and unnecessary data transfers. A layered cache keeps frequently requested data available, while the Build & Test UI reports cache hit rates, build time, and status in real time. The Free tier supports Bazel and provides in-cluster caching on one machine with 32 CPU cores, running Linux. Enterprise supports Bazel, Goma for Chromium, and Soong for AOSP, as well as in-cluster or external storage such as S3 and GCS. Free is self-hosted; Enterprise can be self-hosted or managed. The service is available for Linux, macOS, Windows, web, and API use. EngFlow says builds run in isolated, encrypted environments with dedicated infrastructure by default, and its solutions receive regular third-party audits against the five SOC 2 principles. Free costs nothing; Enterprise pricing is custom quote. A trial request form is available, with no duration stated.