CapsAI

Subtitle file diagnostics

Subtitle Encoding Checker

Diagnose common text-encoding symptoms before a subtitle file reaches your player or editor. The checker reports damaged replacement characters, hidden null bytes, normalization and line-ending details.

Browser-basedFree to use

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Tool workspace

No account required · processed locally

Three steps

How this tool works

  1. 1

    Paste text from an SRT or VTT file.

  2. 2

    Inspect visible and hidden encoding signals.

  3. 3

    Use the report to decide whether to re-export as UTF-8.

Useful for

Common workflows

  • Broken regional-language captions
  • Subtitle import troubleshooting
  • UTF-8 delivery QA

What it checks

Focused, transparent output

  • Unicode replacement characters
  • Null bytes and BOM
  • NFC normalization and line endings

Questions

Frequently asked questions

Can a browser identify the original file encoding with certainty?

Not after text has already been decoded. This tool detects common damage signals and Unicode structure, not the original byte encoding.

What does the replacement character mean?

The symbol � often indicates bytes could not be decoded correctly.

What encoding should I export subtitles with?

UTF-8 is the safest general choice for Indian scripts and multilingual captions.

Continue your subtitle workflow

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