Vineflower can be run as a CLI tool.

java -jar vineflower.jar [args...] {in}+ [{out}]


--cfg=file, -cfg=file#

A configuration file containing additional arguments to pass to the decompiler, one per line.

--add-external=library, -e=library#

Can be specified as many times as necessary to add library inputs to the decompile classpath

The following three options control how decompiled output should be written. If none are specified, the output type will be inferred based on the output. .zip or .jar-ending outputs will be treated as archives, all other values will be treated as a directory, or no output at all will write the decompiled output to the console.


Prefer saving to an archive file.


Prefer saving to a folder, potentially extracting an input archive.


Use legacy Fernflower save behavior.

It is possible to limit decompiled output to only a certain subset of the input files, for cases where an entire archive is provided as input:

--only=prefix, -only=prefix#

Only members whose paths start with prefix will be emitted

--ascii-strings=bool, -asc=bool#

Encode non-ASCII characters in string and character literals as Unicode escapes.

Default: 0

--banner=string, -ban=string#

A message to display at the top of the decompiled file.

--boolean-as-int=bool, -bto=bool#

Represent integers 0 and 1 as booleans.

Default: 1

--bytecode-source-mapping=bool, -bsm=bool#

Map Bytecode to source lines.

Default: 0

--decompile-assert=bool, -das=bool#

Decompile assert statements.

Default: 1

--decompile-complex-constant-dynamic=bool, -dcc=bool#

Some constant-dynamic expressions can’t be converted to a single Java expression with identical run-time behaviour. This decompiles them to a similar non-lazy expression, marked with a comment.

Default: 0

--decompile-enums=bool, -den=bool#

Decompile enums.

Default: 1

--decompile-finally=bool, -fdi=bool#

Decompile finally blocks.

Default: 1

--decompile-generics=bool, -dgs=bool#

Decompile generics in classes, methods, fields, and variables.

Default: 1

--decompile-inner=bool, -din=bool#

Process inner classes and add them to the decompiled output.

Default: 1

--decompile-java4=bool, -dc4=bool#

Resugar the Java 1-4 class reference format instead of leaving the synthetic code.

Default: 1

--decompile-preview=bool, -dpr=bool#

Decompile features marked as preview or incubating in the latest Java versions.

Default: 1

--decompile-switch-expressions=bool, -swe=bool#

Decompile switch expressions in modern Java class files.

Default: 1

--decompiler-comments=bool, -dec=bool#

Sometimes, odd behavior of the bytecode or unfixable problems occur. This enables or disables the adding of those to the decompiled output.

Default: 1

--dump-bytecode-on-error=bool, -dbe=bool#

Put the bytecode in the method body when an error occurs.

Default: 1

--dump-code-lines=bool, -dcl=bool#

Dump line mappings to output archive zip entry extra data.

Default: 0

--dump-exception-on-error=bool, -dee=bool#

Put the exception message in the method body or source file when an error occurs.

Default: 1

--dump-text-tokens=bool, -dtt=bool#

Dump Text Tokens on each class file

Default: 0

--ensure-synchronized-monitors=bool, -esm=bool#

If a synchronized block has a monitorenter without any corresponding monitorexit, try to deduce where one should be to ensure the synchronized is correctly decompiled.

Default: 1

--error-message=string, -erm=string#

Message to display when an error occurs in the decompiler.

Default: Please report this to the Vineflower issue tracker, at with a copy of the class file (if you have the rights to distribute it!)

--explicit-generics=bool, -ega=bool#

Put explicit diamond generic arguments on method calls.

Default: 0

--force-jsr-inline=bool, -fji=bool#

Forces the processing of JSR instructions even if the class files shouldn’t contain it (Java 7+)

Default: 0

--hide-default-constructor=bool, -hdc=bool#

Hide constructors with no parameters and no code.

Default: 1

--hide-empty-super=bool, -hes=bool#

Hide super() calls with no parameters.

Default: 1

--ignore-invalid-bytecode=bool, -iib=bool#

Ignore bytecode that is malformed.

Default: 0

--include-classpath=bool, -iec=bool#

Give the decompiler information about every jar on the classpath.

Default: 0

--include-runtime=string, -jrt=string#

Give the decompiler information about the Java runtime, either 1 or current for the current runtime, or a path to another runtime

--incorporate-returns=bool, -ner=bool#

Integrate returns better in try-catch blocks instead of storing them in a temporary variable.

Default: 1

--indent-string=string, -ind=string#

A string of spaces or tabs that is placed for each indent level.


--inline-simple-lambdas=bool, -isl=bool#

Remove braces on simple, one line, lambda expressions.

Default: 1

--keep-literals=bool, -lit=bool#

Keep NaN, infinities, and pi values as is without resugaring them.

Default: 0

--lambda-to-anonymous-class=bool, -lac=bool#

Decompile lambda expressions as anonymous classes.

Default: 0

--log-level=string, -log=string#

Logging level. Must be one of: ‘info’, ‘debug’, ‘warn’, ‘error’.

Default: INFO

--mark-corresponding-synthetics, -mcs#

Mark lambdas and anonymous and local classes with their respective synthetic constructs

Default: 0

--max-time-per-method=int, -mpm=int#

Maximum time in seconds to process a method. This is deprecated, do not use.

Default: 0

--new-line-separator=bool, -nls=bool#

Use \n instead of \r\n for new lines. Deprecated, do not use.

Default: 1

--override-annotation=bool, -ovr=bool#

Display override annotations for methods known to the decompiler.

Default: 1

--pattern-matching=bool, -pam=bool#

Decompile with if and switch pattern matching enabled.

Default: 1

--preferred-line-length=int, -pll=int#

Max line length before formatting is applied.

Default: 160

--remove-bridge=bool, -rbr=bool#

Removes any methods that are marked as bridge from the decompiled output.

Default: 1

--remove-empty-try-catch=bool, -rer=bool#

Remove try-catch blocks with no code.

Default: 1

--remove-getclass=bool, -rgn=bool#

Remove synthetic getClass() calls created by code such as ‘ Inner()’.

Default: 1

--remove-imports=bool, -rim=bool#

Remove import statements from the decompiled code

Default: 0

--remove-synthetic=bool, -rsy=bool#

Removes any methods and fields that are marked as synthetic from the decompiled output.

Default: 1

--rename-members=bool, -ren=bool#

Rename classes, fields, and methods with a number suffix to help in deobfuscation.

Default: 0

--show-hidden-statements=bool, -shs=bool#

Display hidden code blocks for debugging purposes.

Default: 0

--simplify-stack=bool, -ssp=bool#

Simplify variables across stack bounds to resugar complex statements.

Default: 1

--skip-extra-files=bool, -sef=bool#

Skip copying non-class files from the input folder or file to the output

Default: 0

--sourcefile-comments=bool, -sfc=bool#

Add debug comments showing the class SourceFile attribute if present.

Default: 0

--synthetic-not-set=bool, -nns=bool#

Treat some known structures as synthetic even when not explicitly set.

Default: 0

--ternary-constant-simplification=bool, -tcs=bool#

Fold branches of ternary expressions that have boolean true and false constants.

Default: 0

--ternary-in-if=bool, -tco=bool#

Tries to collapse if statements that have a ternary in their condition.

Default: 1

--thread-count=int, -thr=int#

How many threads to use to decompile.

Default: 4

--try-loop-fix=bool, -tlf=bool#

Fixes rare cases of malformed decompilation when try blocks are found inside of while loops

Default: 1

--undefined-as-object=bool, -uto=bool#

Treat nameless types as java.lang.Object.

Default: 1

--use-lvt-names=bool, -udv=bool#

Use LVT names for local variables and parameters instead of var<index>_<version>.

Default: 1

--use-method-parameters=bool, -ump=bool#

Use method parameter names, as given in the MethodParameters attribute.

Default: 1

--user-renamer-class=string, -urc=string#

Path to a class that implements IIdentifierRenamer.

--verify-anonymous-classes=bool, -vac=bool#

Verify that anonymous classes are local.

Default: 0

--verify-merges=bool, -vvm=bool#

Tries harder to verify the validity of variable merges. If there are strange variable recompilation issues, this is a good place to start.

Default: 0

--warn-inconsistent-inner-attributes=bool, -win=bool#

Warn about inconsistent inner class attributes

Default: 1