What causes "Error: Invalid multi-line string"?

A quoted string is split across multiple lines without proper escaping or heredoc syntax Missing closing quote on the expected line, with content continuing on the next line Copy-pasting multi-line text from comments or documentation directly into a quoted string without adjusting the syntax

Is the "Error: Invalid multi-line string" error serious?

Yes. This is a high-severity error that usually blocks work until it is fixed, but the steps above resolve it.

How to fix Error: Invalid multi-line string in Terraform

TerraformBEGINNERHIGHUpdated Dec 30, 2025· 200 views

The 'Invalid multi-line string' error occurs when you attempt to split quoted strings across multiple lines in Terraform. Quoted strings must remain on a single line—use heredoc syntax or escape sequences for multi-line content.

Quick fix

Fixes Error: Invalid multi-line string

# INCORRECT - String split across lines:
local_file = "/path/to/file/that/
contains/multiple/paths"

# This will trigger: Error: Invalid multi-line string

Identify which string is causing the error
Choose the appropriate syntax for multi-line content
Replace the invalid string with the correct syntax
Handle special characters in your multi-line content

terraform — error

$# INCORRECT - String split across lines:
local_file = "/path/to/file/that/
contains/multiple/paths"
# This will trigger: Error: Invalid multi-line string
Error: Invalid multi-line string

What this error means

Terraform's configuration language requires that quoted strings (enclosed in double quotes) be contained entirely on a single line. Attempting to split a quoted string across multiple lines—like starting a string on one line with an opening quote and continuing it on the next line—violates this syntax rule. The error message typically says: 'Quoted strings may not be split over multiple lines. To produce a multi-line string, either use the \n escape to represent a newline character or use the heredoc multi-line template syntax.' This is a parsing error that Terraform encounters during the configuration validation phase. The parser cannot correctly interpret strings that span multiple lines when they're using quoted string syntax, as it expects the closing quote to appear on the same line as the opening quote.

Typical symptoms

Terraform fails during 'terraform init', 'terraform validate', or 'terraform plan' with 'Error: Invalid multi-line string' message
Configuration contains a string value that starts on one line and continues on the next line with quotes
Error points to a specific line number where a string is expected to end but doesn't
Other parts of your configuration are syntactically correct but this particular string fails
The issue appears when copying multi-line text from documentation or other sources into string values

Common causes

A quoted string is split across multiple lines without proper escaping or heredoc syntax
Missing closing quote on the expected line, with content continuing on the next line
Copy-pasting multi-line text from comments or documentation directly into a quoted string without adjusting the syntax
Formatting attempts that accidentally split a string across lines when trying to improve readability
Using a quoted string when you actually intended to use heredoc (<<EOF) syntax for multi-line content
Mixing of shell script or other language conventions where multi-line strings are handled differently

How to fix "Error: Invalid multi-line string"

1Identify which string is causing the error

The Terraform error message will show you the exact line number where the parse error occurred. Look at that line and the lines around it in your .tf file to find the problematic string.

hcl

# INCORRECT - String split across lines:
local_file = "/path/to/file/that/
contains/multiple/paths"

# This will trigger: Error: Invalid multi-line string

Use your editor's line numbering or the error message line reference to quickly locate the issue. The problematic string will be the one using quotes that extends beyond a single line.

2Choose the appropriate syntax for multi-line content

Terraform offers three ways to handle content that spans multiple lines. Choose the one that fits your use case:

Option 1: Use heredoc syntax (recommended for true multi-line strings)

hcl

user_data = <<EOF
#!/bin/bash
echo 'Hello World'
echo 'Installing packages'
apt-get update
EOF

Heredoc syntax uses <<IDENTIFIER to start and must have the identifier on its own line to end. Content between is literal (no quote escaping needed).

Option 2: Use indented heredoc for cleaner formatting

hcl

script_content = <<-EOT
  #!/bin/bash
  echo 'This is indented'
  echo 'Terraform will dedent it automatically'
EOT

The <<- variant allows you to indent the closing marker and content, making code more readable.

Option 3: Use escape sequences for simple line breaks

hcl

message = "Line 1\nLine 2\nLine 3"
description = "This is a long string that needs a break\nwith explicit newline characters"

Use \n for newlines, \t for tabs, and \\ for literal backslashes within a single-line quoted string.

3Replace the invalid string with the correct syntax

Take your problematic multi-line string and rewrite it using one of the three approaches above.

Example conversion:

Before (incorrect):

hcl

resource "aws_instance" "example" {
  user_data = "#!/bin/bash
edit configuration file
install software"
}

After (correct - using heredoc):

hcl

resource "aws_instance" "example" {
  user_data = <<EOF
#!/bin/bash
edit configuration file
install software
EOF
}

Or after (correct - using escape sequences):

hcl

resource "aws_instance" "example" {
  user_data = "#!/bin/bash\nedit configuration file\ninstall software"
}

Choose heredoc for readability when dealing with scripts or large blocks of text. Use escape sequences for shorter strings where inline text is acceptable.

4Handle special characters in your multi-line content

When using heredoc, be aware of how special characters are handled:

In quoted strings (with escape sequences):
- \n → newline
- \t → tab
- \" → literal quote
- \\ → literal backslash
- ${...} → interpolation (use \${...} to escape)
- %{...} → directives (use %{~ ...} to strip whitespace)

In heredoc strings:

hcl

config = <<EOC
No escape sequences needed here
Backslashes are literal: C:\\Users\\Data
But interpolation still works: ${var.name}
End marker EOC must be at line start
EOC

Heredoc preserves literal backslashes and spaces, making them ideal for configuration files, scripts, and data that shouldn't be escaped. Use <<- if you want to indent the closing marker.

5Validate your corrected configuration

After fixing the string syntax, validate that your configuration is now correct:

bash

# Validate the syntax
terraform validate

# Check for other issues and format
terraform fmt -recursive

# Generate a plan to ensure resources are understood correctly
terraform plan

The terraform validate command will parse all your .tf files and report any remaining syntax errors. If you see 'Success! The configuration is valid', the multi-line string error is resolved. If you still get parsing errors, review the error line number and apply the same fix to any other problematic strings.

Advanced notes

When working with complex multi-line content like JSON, YAML, or shell scripts, heredoc is typically the best choice because it avoids the need to escape quotes and special characters. For JSON/YAML, consider using jsonencode() or yamlencode() functions with variables rather than inline strings. If you're generating Terraform code (using tools like Terragrunt or CDK for Terraform), ensure the code generator is outputting valid HCL syntax. Interpolation like ${var.example} continues to work inside heredoc blocks unless you prefix with ~ for directive-style stripping. When copying code from GitHub or documentation, be careful to preserve the original line structure—web browsers sometimes mangle whitespace and line breaks. For reusable multi-line content across multiple resources, consider storing the content in variables or local values, then reference them. This improves maintainability and makes the syntax cleaner.

Frequently asked questions

What does "Error: Invalid multi-line string" mean?: Terraform's configuration language requires that quoted strings (enclosed in double quotes) be contained entirely on a single line. Attempting to split a quoted string across multiple lines—like starting a string on one line with an opening quote and continuing it on the next line—violates this syntax rule. The error message typically says: 'Quoted strings may not be split over multiple lines.
How do I fix "Error: Invalid multi-line string"?: The 'Invalid multi-line string' error occurs when you attempt to split quoted strings across multiple lines in Terraform. Quoted strings must remain on a single line—use heredoc syntax or escape sequences for multi-line content.
What causes "Error: Invalid multi-line string"?: A quoted string is split across multiple lines without proper escaping or heredoc syntax Missing closing quote on the expected line, with content continuing on the next line Copy-pasting multi-line text from comments or documentation directly into a quoted string without adjusting the syntax
Is the "Error: Invalid multi-line string" error serious?: Yes. This is a high-severity error that usually blocks work until it is fixed, but the steps above resolve it.