Open GEM files in your browser
A Ruby library as RubyGems installs it. Open one right here to see what it needs, what runs as it installs and whether its files are whole. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your app opens like a folder, its files listed on the left, with a page beside them on what it is, who signed it and what it asks for.
- Its signature • Checked inside your browser
- SHA-256 • Compare it or look it up on VirusTotal
- Heads-ups • What it asks for and what runs
- Its files • Manifests open as text
About GEM
A gem is a TAR of three members: metadata.gz, its gemspec as YAML, with the gem's name, version, authors and dependencies, data.tar.gz with its files, and checksums.yaml.gz with the SHA-256 and SHA-512 of the other two.
A gem with native extensions compiles them as it installs, running its extconf.rb with your rights. A few gems are signed: a .sig beside each member, made with a certificate their author made, which RubyGems only trusts once you add it yourself.
Filepeek checks metadata.gz and data.tar.gz against the checksums, and each signature with the certificate the gemspec carries. It reads the gemspec for the gem's details and dependencies, and lists the commands it installs and the extensions it builds.
Ruby gem
.gem
Format
- MIME type
- application/x-tar
- Made by
- RubyGems
- Released
- 2004
Inside the file
- Container
- TAR
- Details
- metadata.gz, a gemspec as YAML
- Files
- data.tar.gz
- Checks
- checksums.yaml.gz, and a .sig per member
Opens in every browser
No browser opens a GEM: they download it. Filepeek opens it as a folder in Chrome, Edge, Firefox and Safari.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Questions
How do I see what a Ruby gem holds?
Drop it on this page or choose Peek a GEM. A page shows the gem, what it needs, the commands it installs and the native code it builds, and its files are listed like a folder.
Can I check a gem's signature?
Yes, when it's signed. Filepeek checks each .sig with the certificate in its gemspec and says when that certificate expired. Every gem's files are checked against its checksums.
How do I look up a GEM on VirusTotal?
Filepeek works out its SHA-256 inside your browser. Look up on VirusTotal opens VirusTotal's page for that hash, and only the hash goes, never the file. Compare checks it against a SHA-256, SHA-1 or MD5 you paste.
Does opening a GEM install it?
No. Filepeek only reads it: nothing in it runs, nothing is installed and it never leaves your device.
Can I get files out of a GEM?
Yes. Pick any file on the left to open it. Its gemspec and code open as text. Export saves them all as a ZIP, or, in Chrome and Edge on a computer, extracts them into a folder.