Version 3.0 is under development, as of March 2021 (and since late 2017).

It is a major version update and thereby not API compatible with 2.x; however, since 2.10 new methods have been added in 2.x line to reduce incompatibilities.

Overall plans are outlined in JSTEP-1

Java 8 is now required for all components.

1. Removal of all deprecated methods, functionality, as of 2.x
   • Remove format-auto-detection (interesting idea but not widely used and few formats beyond JSON, XML, Smile, Avro support detection)
2. Full immutability of core entities, via Builder-style construction
   • TokenStreamFactory (old JsonFactory)
   • ObjectMapper (addition of format-specific sub-classes, from JsonMapper to XmlMapper)
   • Note Jackson 2.10 and later will also support most of Builder-style construction but without strict guarantees of immutability of underlying entities (due to backwards-compatibility reasons)
   • See Jackson 3 immutability with builders
3. Tighter integration between Streaming and Databinding to allow improved support of non-JSON formats
   • ObjectMapper remains shared API, but every format will have its own mapper subtype, including JsonMapper for JSON
     • Partly implemented in 2.x since 2.10, to support Builder-style construction (albeit without immutability)
   • Format-specific mapper will (have to) use format-specific TokenStreamFactory
4. Unchecked exceptions (see JSTEP-4
   • Base 2.x exceptions will be replaced with new counterparts as follows (counterparts will be added in 2.x but mostly used in 3.0)
   • JsonProcessingException (root exception) becomes JacksonException
   • JsonParseException/JsonGenerationException (streaming) will become StreamReadException/StreamWriteException
   • JsonMappingException (root for databind exceptions) becomes DatabindException
   • While new exceptions will be added by Jackson 2.13, their use is limited: they CAN be caught but NOT thrown (sort of "read-only" upgrade) while retaining compatibility across minor versions

• #378: Change default for TokenStreamFactory.Feature.INTERN_FIELD_NAMES to false
• #402: Remove dataformat-auto-detection functionality
• #411: Rename JsonStreamContext as TokenStreamContext
• #413: Remove ObjectCodec: replace with ObjectWriteContext / ObjectReadContext
• #432: Add new TreeNode subtypes: ArrayTreeNode, ObjectTreeNode
• #433: Add Builder pattern for creating configured Stream factories
• #456: Add JsonParser.readAsValue(ResolvedType)
• #492: Ensure primitive type names in error message enclosed in backticks
• #551: Remove JsonGenerator.setPrettyPrinter() from 3.0
• #663: Rename JsonEOFException as UnexpectedEndOfInputException
• #670: Replace references to "field" in JsonGenerator, JsonParser method names with "property"
• #671: Replace getCurrentLocation()/getTokenLocation() with currentLocation()/currentTokenLocation()
• #676: Remove JsonGenerator.canWriteBinaryNatively(), canWriteFormattedNumbers() (replaced by StreamWriteCapability equivalents)
• #680: Allow use of java.nio.file.Path as parser source, generator target
• #689: Remove existing "request payload" functionality
• #785: Make JsonGenerator.writeXxx() methods chainable
• #793: Rename "com.fasterxml.jackson" -> "tools.jackson"
• #1090: Remove BufferRecyclers.SYSTEM_PROPERTY_TRACK_REUSABLE_BUFFERS
• #1125: Remove TokenStreamFactory.Feature.USE_THREAD_LOCAL_FOR_BUFFER_RECYCLING
• #1200: Change JsonWriteFeature.ESCAPE_FORWARD_SLASHES default to true for 3.0
• #1231: Enable Fast Floating-Point reading/writing by default in 3.0
• #1233: Lower default maxNestingDepth of StreamReadConstraints / StreamWriteConstraints to 500 in 3.0
• #1269: Change JsonFactory.builder() configuration of RecyclerPool to avoid allocation default implementation (in 3.0)
• Rename JsonGenerator.Feature.AUTO_CLOSE_JSON_CONTENT as AUTO_CLOSE_CONTENT
• Add TreeCodec.nullNode(), TreeNode.isNull() methods
• Change the way JsonLocation.NA is included in exception messages

• #1772: Remove MapperFeature. USE_STD_BEAN_NAMING
• #1773: Remove MapperFeature.AUTO_DETECT_xxx features
• #1917: Remove canSerialize and canDeserialize methods from ObjectMapper
• #1973: Remove support for "default [Map] key serializer" configuration from SerializerProvider
• #2040: Remove JsonSerializer.isEmpty()
• #4160: Deprecate DefaultTyping.EVERYTHING in 2.x and remove in 3.0
• Remove MappingJsonFactory

• #1600: Serializing locale with underscore, not standard hyphen
• #1762: StdDateFormat: serialize time offset using colon
• #1774: Merge Java8 datatype (Optional, Stream) support in core databind
• #1775: Merge Java8 parameter name support (jackson-module-parameter-names) in core databind
• #1781: Return ObjectNode from ObjectNode set-methods in order to allow better chaining
• #:
• #1888: Merge ResolvableSerializer into JsonSerializer, ResolvableDeserializer into JsonDeserializer
• #1889: Merge ContextualSerializer into JsonSerializer, ContextualDeserializer into JsonDeserializer
• #1916: Change MapperFeature.USE_GETTERS_AS_SETTERS) default to false
• #1994: Limit size of SerializerCache, auto-flush on exceeding
• #1995: Limit size of DeserializerCache, auto-flush on exceeding
• #2177: Change parent type of JsonProcessingException to be RuntimeException
• #2713: Change wording of UnrecognizedPropertyException to refer to "property" not "field"
• #3028: Change UUIDSerializer to use StreamWriteCapability check instead of JsonGenerator.canWriteBinaryNatively()
• #4381: Prevent construction of null-valued JsonNodes (like TextNode)

• #3037: Rename Module as JacksonModule in 3.0 (to avoid overlap with java.lang.Module)
• #3044: Rename JsonDeserializer/JsonSerializer as ValueDeserializer/ValueSerializer
• #3046: Rename JsonSerializable as JacksonSerializable
• #3047: Rename Bean[De]SerializerModifier as Value[De]SerializerModifier

• #1789: Add createGenerator methods in ObjectMapper, ObjectWriter
• #1790: Add createParser methods in ObjectMapper, ObjectReader
• #1883: Add "abstract type mapping" for deserialization from Map<ENUMTYPE,V> into EnumMap (and Set<ENUMTYPE> to EnumSet<EnumType>)
• #1954: Add Builder pattern for creating configured ObjectMapper instances
• #1955: Change the way Modules configure, interact with ObjectMapper
• #2013: Allow use of java.nio.file.Path for readValue(), writeValue()
• #2411: valueToTree() during serialization (via SerializerProvider())
• #2828: Add DatabindException as intermediate subtype of JsonMappingException
• #3536: Create new exception type JsonNodeException for use by JsonNode-related problems

• #24: Support for Guava's Immutable{Double,Int,Long}Array
• #69: Add support for Guava primitives during deserialization