Python & JavaScript SyntaxError Reference: 48+ Parsing & Syntax Fixes (2026)

itsourcecode.com hosts 48+ documented fixes for SyntaxError messages in both Python and JavaScript, the error class raised when the parser encounters code it can’t interpret. Unlike runtime errors, syntax errors are caught before code executes. Most come from missing/extra punctuation, mismatched quotes, missing colons (Python), mixed module/script boundaries (JavaScript ES Modules), or wrong Python version targeting. Browse the fixes below by language.
What is a SyntaxError?
A SyntaxError is raised when the language parser fails to understand your code, meaning the code is structurally invalid before it can run. In Python, SyntaxError is detected at import or first execution; in JavaScript, by the browser or Node.js when the file is loaded. The error message usually points to the line and column where the parser got confused. Often the actual mistake is on the LINE BEFORE the one reported (a missing comma, paren, or colon).
How to debug any SyntaxError in 4 steps

Look at the line BEFORE the reported error. Parsers often only realize something’s wrong on the next line. A missing closing paren on line 10 is often reported as “unexpected token” on line 11.
Match all opening/closing pairs. ( with ), [ with ], { with }, " with ", ' with '. Most syntax errors are one missing or extra character. Editor bracket-matching helps a lot.
Check your Python or Node version. Modern features (walrus operator :=, f-strings, match statement, ESM import.meta) require a specific minimum version. If the syntax is fine but you’re on an old runtime, the parser doesn’t recognize it.
For JSON errors, validate with a JSON formatter. “Unexpected token” in JSON usually means trailing commas, single quotes (JSON requires double), or unescaped characters. Paste into jsonlint.com.

Featured SyntaxError fixes by language
🐍 Python: invalid syntax / EOF / EOL

SyntaxError: invalid syntax (Troubleshooting Guide)
SyntaxError: unexpected EOF while parsing
SyntaxError: EOL while scanning string literal
SyntaxError: unexpected character after line continuation

🐍 Python: statement structure

Expected ‘except’ or ‘finally’ block
Multiple exception types must be parenthesized
Generator expression must be parenthesized
‘return’ outside function
Positional argument follows keyword argument
f-string expression part cannot include a backslash
future feature ‘annotations’ is not defined (Python 3.7+)

🟦 JavaScript: unexpected token

Uncaught SyntaxError: Unexpected number
SyntaxError: Unexpected token ‘export’
Uncaught SyntaxError: missing ) after argument list
Uncaught SyntaxError: Invalid left-hand side in assignment
Uncaught SyntaxError: Invalid or unexpected token
Uncaught SyntaxError: Invalid shorthand property initializer
Uncaught SyntaxError: Unexpected end of input (in promise)

🟦 JavaScript: ES Modules & modern syntax

SyntaxError: Cannot use ‘import.meta’ outside a module
Missing initializer in const declaration
Unexpected reserved word ‘await’ (outside async)
‘import’ and ‘export’ may appear only with sourceType: ‘module’ (ESLint)

📦 JSON parsing errors

Unexpected token ‘o’ in JSON at position 1
Expression.SyntaxError: Token EOF expected (PowerQuery)

Related error categories
SyntaxError is one of 10 hubs in our Python & JavaScript error reference cluster, 980+ documented fixes total:

TypeError Reference, 220+ Python & JS TypeError fixes
ModuleNotFoundError Reference, 198+ Python import errors
AttributeError Reference, 173+ “object has no attribute X” fixes
ValueError Reference, 100+ pandas/NumPy/sklearn fixes
ImportError Reference, 67+ “cannot import name X from Y” fixes
NameError Reference, 49+ “name X is not defined” fixes
RuntimeError Reference, 49+ PyTorch/CUDA/async runtime errors
ReferenceError Reference, 34+ JavaScript “is not defined” fixes
HTTP Error Reference, 35+ HTTP status code fixes (4xx, 5xx)
Python Tutorial, beginner-to-intermediate Python lessons

About this SyntaxError reference
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