[**API**][cljdoc] | [**Wiki**][GitHub wiki] | [Latest releases](#latest-releases) | [Get support][GitHub issues] # Nippy ### Fast serialization library for Clojure Clojure's rich data types are awesome. And its [reader](https://clojure.org/reference/reader) allows you to take your data just about anywhere. But the reader can be painfully slow when you've got a lot of data to crunch (like when you're serializing to a database). Nippy is a mature, high-performance **drop-in alternative to the reader**. It is used at scale by [Carmine](https://www.taoensso.com/carmine), [Faraday](https://www.taoensso.com/faraday), [PigPen](https://github.com/Netflix/PigPen), [Onyx](https://github.com/onyx-platform/onyx), [XTDB](https://github.com/xtdb/xtdb), [Datalevin](https://github.com/juji-io/datalevin), and others. ## Latest release/s - `2025-04-15` `v3.5.0`: [release info](../../releases/tag/v3.5.0) [![Main tests][Main tests SVG]][Main tests URL] [![Graal tests][Graal tests SVG]][Graal tests URL] See [here][GitHub releases] for earlier releases. ## Why Nippy? - Small, simple **pure-Clojure** library - **Terrific performance**: the [best](#performance) for Clojure that I'm aware of - Comprehensive support for [all standard data types](../../wiki/1-Getting-started#deserializing) - Easily extendable to [custom data types](../../wiki/1-Getting-started#custom-types) - **Robust test suite** incl. coverage of every supported type - **Mature** and widely used in production for 12+ years - Optional auto fallback to [Java Serializable](https://taoensso.github.io/nippy/taoensso.nippy.html#var-*freeze-serializable-allowlist*) for [safe](https://cljdoc.org/d/com.taoensso/nippy/CURRENT/api/taoensso.nippy#*freeze-serializable-allowlist*) types - Optional auto fallback to Clojure Reader (including tagged literals) - Optional smart **compression** with [LZ4](https://code.google.com/p/lz4/) or [Zstandard](https://facebook.github.io/zstd/) - Optional [encryption](../../wiki/1-Getting-started#encryption) with AES128 - [Tools](https://taoensso.github.io/nippy/taoensso.nippy.tools.html) for easy + robust **integration into 3rd-party libraries**, etc. - Powerful [thaw transducer](https://taoensso.github.io/nippy/taoensso.nippy.html#var-*thaw-xform*) for flexible data inspection and transformation ## Quick example Nippy's super easy to use: ```clojure (require '[taoensso.nippy :as nippy]) ;; Freeze any Clojure value (nippy/freeze ) ; => Serialized byte[] ;; Thaw the byte[] to get back the original value: (nippy/thaw (nippy/freeze )) ; => ``` See the [wiki](https://github.com/taoensso/nippy/wiki/1-Getting-started#deserializing) for more. ## Operational considerations ### Data longevity Nippy is widely used to store **long-lived** data and promises (as always) that **data serialized today should be readable by all future versions of Nippy**. But please note that the **converse is not generally true**: - Nippy `vX` **should** be able to read all data from Nippy `vY<=X` (backwards compatibility) - Nippy `vX` **may/not** be able to read all data from Nippy `vY>X` (forwards compatibility) ### Rolling updates and rollback From time to time, Nippy may introduce: - Support for serializing **new types** - Optimizations to the serialization of **pre-existing types** To help ease **rolling updates** and to better support **rollback**, Nippy (since version v3.4) will always introduce such changes over **two version releases**: - Release 1: to add **read support** for the new types - Release 2: to add **write support** for the new types Starting from v3.4, Nippy's release notes will **always clearly indicate** if a particular update sequence is recommended. ### Stability of byte output It has **never been an objective** of Nippy to offer **predictable byte output**, and I'd generally **recommend against** depending on specific byte output. However, I know that a small minority of users *do* have specialized needs in this area. So starting with Nippy v3.4, Nippy's release notes will **always clearly indicate** if any changes to byte output are expected. ## Performance Nippy is fast! Latest [benchmark](../../blob/master/test/taoensso/nippy_benchmarks.clj) results:  PRs welcome to include other alternatives in the bench suite! ## Documentation - [Wiki][GitHub wiki] (getting started, usage, etc.) - API reference via [cljdoc][cljdoc] ## Funding You can [help support][sponsor] continued work on this project, thank you!! 🙏 ## License Copyright © 2012-2025 [Peter Taoussanis][]. Licensed under [EPL 1.0](LICENSE.txt) (same as Clojure). [GitHub releases]: ../../releases [GitHub issues]: ../../issues [GitHub wiki]: ../../wiki [Peter Taoussanis]: https://www.taoensso.com [sponsor]: https://www.taoensso.com/sponsor [cljdoc]: https://cljdoc.org/d/com.taoensso/nippy/CURRENT/api/taoensso.nippy [Clojars SVG]: https://img.shields.io/clojars/v/com.taoensso/nippy.svg [Clojars URL]: https://clojars.org/com.taoensso/nippy [Main tests SVG]: https://github.com/taoensso/nippy/actions/workflows/main-tests.yml/badge.svg [Main tests URL]: https://github.com/taoensso/nippy/actions/workflows/main-tests.yml [Graal tests SVG]: https://github.com/taoensso/nippy/actions/workflows/graal-tests.yml/badge.svg [Graal tests URL]: https://github.com/taoensso/nippy/actions/workflows/graal-tests.yml