What is the JSXBIN file format?
Despite its name, a .jsxbin file is an ASCII text file - not a true binary. It is the compiled output of Adobe ExtendScript Toolkit (ESTK), produced when a developer exports a .jsx script in encoded form. The encoding serializes the parsed abstract syntax tree (AST) of the ExtendScript source into a base64-like ASCII representation intended to deter casual inspection.
Every .jsxbin file begins with the plaintext header @JSXBIN@[email protected]@ (or @JSXBIN@[email protected]@ for scripts compiled in CS4 and earlier), followed by one encoded AST node per line. The format provides obfuscation, not true encryption - third-party decompilers can reconstruct near-original source, though variable names are typically mangled.
.jsxbin scripts run natively inside Adobe Creative Cloud applications including Photoshop, Illustrator, InDesign, and After Effects. Developers use this format to distribute automation scripts commercially while protecting intellectual property from easy copying.
Adobe ExtendScript and ESTK are considered legacy technology. The modern replacement is the UXP (Unified Extensibility Platform), which uses HTML, CSS, and standard JavaScript. UXP plugins target Photoshop 2021+, InDesign 2022+, and later. Despite this transition, many production workflows in publishing, broadcast, and prepress continue to rely on ExtendScript automation, so .jsxbin files remain in active use.
Security & safety
RISK: MEDIUMJSXBIN scripts run with the privileges of the Adobe host application and can perform file system operations, execute shell commands (via system.callSystem in ExtendScript), and access network resources. Malicious JSXBIN scripts have been observed in the wild (Hexacorn documented JSX/JSXBIN abuse in 2022). Always obtain scripts from trusted vendors. The VS Code ExtendScript Debugger can help audit scripts before running.
Format details
in a nutshellPrograms that open JSXBIN files
Windows5 apps
Adobe ExtendScript Toolkit (ESTK)
Free (discontinued, no longer downloadab Open .jsxbin for debugging - discontinued, use VS Code ExtendScript Debugger instead. 
macOS2 apps
Technical details
deep spec| File header | `@JSXBIN@[email protected]@` (ASCII text, first line) or `@JSXBIN@[email protected]@` for CS4-era scripts |
| Encoding | ASCII - base64-like serialization of the compiled abstract syntax tree |
| Format versions | 1.0 (CS4 and earlier), 2.0 (CS5 and later); version declared in the header line |
| Container | Plain text file with ASCII-encoded payload; one AST node per line after the header |
| Encryption | None - obfuscation only; reversible by third-party decompilers |
| Typical file size | 5 KB - 500 KB depending on script complexity |
| OS support | Windows, macOS |
| MIME type | application/octet-stream (also recognized as text/plain) |
| Decompilability | Yes - third-party tools can recover near-original JSX source with mangled variable names |
| SDK status | Adobe ExtendScript Toolkit (ESTK) discontinued; Photoshop, Illustrator, InDesign, and After Effects still execute JSXBIN natively |
| Successor platform | UXP (Unified Extensibility Platform) using .js/.ts source - Photoshop 2021+, InDesign 2022+ |
| Developer | Adobe Systems Incorporated |
| Introduced | 2004 with Adobe Creative Suite and ExtendScript Toolkit |
| Released | 2004 (Adobe Creative Suite CS, ExtendScript Toolkit) |
| Latest version | JSXBIN version 2.0 (ES / ExtendScript) |
| Specification | extendscript.docsforadobe.dev |
JSXBIN conversions
Community Q&A
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