ASN1C 7.9.0 was released on March 4, 2025. New features in this release include the following:

• Support has been added for aligned PER (PER), unaligned PER (UPER), and OER encoding and decoding in Python.
• Support has been added for .NET v7 through .NET v9 as well as .NET Standard v2.
• The number of source files generated when -depends is used has been reduced. Before, source files for some unused import files were added. These have now been removed.
• A new asn1names print format (-prtfmt asn1names) is now supported, in addition to bractext and details. The new format will use ASN.1 names in generated print output where possible rather than program language names.
• Use of the -strict qualifier will now cause constraint violations seen during C/C++ decoding to be treated as fatal errors.
• The -hexstr option has been added to generated reader programs to allow a hexadecimal string to be passed into a reader for decoding.
• Dark mode added to the ASN1C GUI.
• For Go language code generation, if one binary encoding rule (e.g. -ber, -per) and one text encoding rule (either -xml or -json) are selected, the generated main.go file writer first decodes a text representation of the message using the text encoding rule and will then encode a binary representation of the message using the binary encoding rule. The reader will do the opposite: decode the binary message and encode into the textual format.

The following defects were fixed in this release:

• Fixed a bug in golang JSON BIT STRING unmarshalling code in which a zero length string would cause an error.