ohler55/oj has 3,229 GitHub stars and 274 forks. GitHot measured +1 stars in 24 hours. Last checked 2026-11-07 18:03 UTC. Last push 2026-11-02.
Optimized JSON
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README.md
Original
gem
A fast JSON parser and Object marshaller as a Ruby gem.
Version 3.13 is out with a much faster parser (Oj::Parser) and option isolation.
Using
require 'oj'
h = { 'one' => 1, 'array' => [ true, false ] }
json = Oj.dump(h)
# json =
# {
# "one":1,
# "array":[
# true,
# false
# ]
# }
h2 = Oj.load(json)
puts "Same? #{h == h2}"
# true
Installation
gem install oj
or in Bundler:
gem 'oj'
Rails and json quickstart
See the Quickstart sections of the Rails and json docs.
Support
Get supported Oj with a Tidelift Subscription. Security updates are supported.
Further Reading
For more details on options, modes, advanced features, and more follow these links.
- {file:Options.md} for parse and dump options.
- {file:Modes.md} for details on modes for strict JSON compliance, mimicking the JSON gem, and mimicking Rails and ActiveSupport behavior.
- {file:JsonGem.md} includes more details on json gem compatibility and use.
- {file:Rails.md} includes more details on Rails and ActiveSupport compatibility and use.
- {file:Custom.md} includes more details on Custom mode.
- {file:Encoding.md} describes the :object encoding format.
- {file:Compatibility.md} lists current compatibility with Rubys and Rails.
- {file:Advanced.md} for fast parser and marshalling features.
- {file:Security.md} for security considerations.
- {file:InstallOptions.md} for install option.
Releases
See {file:CHANGELOG.md} and {file:RELEASE_NOTES.md}
Links
Documentation: http://www.ohler.com/oj/doc, http://rubydoc.info/gems/oj
GitHub repo: https://github.com/ohler55/oj
RubyGems repo: https://rubygems.org/gems/oj
Links of Interest
Fast XML parser and marshaller on RubyGems: https://rubygems.org/gems/ox
Fast XML parser and marshaller on GitHub: https://github.com/ohler55/ox
Need for Speed for an overview of how Oj::Doc was designed.
OjC, a C JSON parser: https://www.ohler.com/ojc also at https://github.com/ohler55/ojc
Agoo, a high performance Ruby web server supporting GraphQL on GitHub: https://github.com/ohler55/agoo
Agoo-C, a high performance C web server supporting GraphQL on GitHub: https://github.com/ohler55/agoo-c
oj-introspect, an example of creating an Oj parser extension in C: https://github.com/meinac/oj-introspect
Contributing
- Provide a Pull Request off the
developbranch. - Report a bug
- Suggest an idea
- Code is now formatted with the clang-format tool with the configuration file in the root of the repo.
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