File Splitter & Joiner is part of DevStudio — a free, in-browser collection of developer utilities that work without sign-up, installation, or any backend service. Split multiple large files into chunks and join parts back together with progress tracking, all running entirely on your device. Because the page never uploads what you paste, you can run sensitive payloads, configuration files, secrets, or production data through it with confidence: nothing leaves your browser tab. Use File Splitter & Joiner for ad-hoc debugging, code review, log triage, release prep, learning a new format, or as a quick scratchpad while you build. If you use this tool a lot, pair it with Random File Generator, File Compressor, UUID / ULID, and the rest of the DevStudio toolkit for related developer workflows.