The aeson package

[Tags: bsd3, library]

A JSON parsing and encoding library optimized for ease of use and high performance.

To get started, see the documentation for the Data.Aeson module below.

Parsing performance on a late 2013 MacBook Pro (2.6GHz Core i7), running 64-bit GHC 7.10.1, for mostly-English tweets from Twitter's JSON search API:

Encoding performance on the same machine and data:

(A note on naming: in Greek mythology, Aeson was the father of Jason.)

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Versions0.1.0.0,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, (info)
Dependenciesattoparsec (>=, base (>=4.5 && <5), bytestring (>=, containers, deepseq, dlist (>=0.2), ghc-prim (>=0.2), hashable (>=, mtl, old-locale, scientific (>=0.3.1 && <0.4), syb, template-haskell (>=2.7), text (>=, time, transformers, unordered-containers (>=, vector (>=0.7.1) [details]
Copyright(c) 2011-2015 Bryan O'Sullivan (c) 2011 MailRank, Inc.
AuthorBryan O'Sullivan <>
MaintainerBryan O'Sullivan <>
CategoryText, Web, JSON
Home page
Bug tracker
Source repositoryhead: git clone git://
head: hg clone
UploadedFri Sep 18 17:02:55 UTC 2015 by BryanOSullivan
DistributionsDebian:, Fedora:, FreeBSD:, LTSHaskell:, NixOS:, Stackage:
Downloads226889 total (1629 in last 30 days)
8 []
StatusDocs available [build log]
Last success reported on 2015-09-18 [all 1 reports]




developeroperate in developer modeDisabledManual
old-localeIf false then depend on time >= 1.5. If true then depend on time < 1.5 together with old-locale.DisabledAutomatic

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info


Maintainers' corner

For package maintainers and hackage trustees

Readme for aeson-

Welcome to aeson

aeson is a fast Haskell library for working with JSON data.

Join in!

We are happy to receive bug reports, fixes, documentation enhancements, and other improvements.

Please report bugs via the github issue tracker.

Master git repository:

There's also a Mercurial mirror:

(You can create and contribute changes using either git or Mercurial.)


This library is written and maintained by Bryan O'Sullivan,