# EsotericSoftware/kryo

Java binary serialization and cloning: fast, efficient, automatic

Repository: https://github.com/EsotericSoftware/kryo
Canonical: https://ross.abutalabs.com/products/kryo
Language: HTML
License: BSD-3-Clause
License Family: permissive
Topics: java, serialization, cloning, kryo
Last push: 2026-08-24T12:00:32+00:00

## Health v2 (maintenance only)
Score: 79/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 40, longevity 100
- inputs: {"age_days": 4683, "days_push": 9, "days_rel": 692, "gap_med": 3, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6546, forks 841 (observed 2026-08-28T04:09:45.116936+00:00)

## What it is
Kryo is a fast and efficient binary object graph serialization framework for Java with an easy-to-use API. It also supports automatic deep and shallow object copying without going through bytes.

## Use cases
- serialize java objects to binary for persistence
- send objects over the network efficiently
- deep clone object graphs in java
- reduce serialized payload size
- fast serialization for caching or messaging

## When to choose
- you need high-performance binary serialization on the JVM
- you want automatic serialization of arbitrary object graphs
- you need direct deep/shallow object cloning

## When to avoid
- you need human-readable or cross-language formats like JSON or protobuf
- you require strict schema evolution and interoperability across platforms
- you serialize untrusted data without careful deserialization limits

## Facets
- artifact type: library
- maturity: stable
- function: serialization, developer-tools
- domain: developer-tools, databases, microservices
- platform: jvm, cross-platform
- tags: object-graph-serialization, deep-cloning, binary-format, performance

## Member repositories
- EsotericSoftware/kryo (main) score 79

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:45.116936+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:44:05.376577+00:00, confidence not recorded.
  - readme: https://github.com/EsotericSoftware/kryo (fetched 2026-08-28T04:09:45.116936+00:00, sha 416eedb71daf)
- Data as of 2026-08-30T08:39:29.467469+00:00.