Legacy JavaScript Escape Converter

Inspect legacy JavaScript escape() and unescape() text for compatibility. This is encoding, not encryption, and modern URI work should use encodeURIComponent().

What this legacy API actually does

escape() converts characters into an older percent-based representation and may emit non-standard %uXXXX sequences. unescape() reverses that representation. The result is readable and reversible, so it must not be described or used as encryption.

Use only when diagnosing data produced by an older browser script.
For URL query values, prefer encodeURIComponent() and decodeURIComponent().
Test non-ASCII input because %uXXXX is not standard URI percent-encoding.

Compatibility check

Record the exact input and expected legacy output before replacing an old call. A safe migration test compares the historical result with the modern URI-encoding result and confirms which downstream system expects each format.

Reference: ECMAScript Annex B legacy web features.

Usage boundaries and result checks

Legacy JavaScript Escape Converter is for this task: Inspect legacy JavaScript escape/unescape text for compatibility; this is encoding, not encryption. It runs in the browser; start with a short, non-sensitive sample and confirm the behavior before processing more data.

Best use

Use it for a focused Legacy JavaScript Escape Converter task when a quick browser workbench is appropriate.

Input

text, an encoded string, or the data format named by the tool

Output

an encoded, decoded, or compatibility-check result

Before reuse

For Legacy JavaScript Escape Converter: Confirm the character set, byte boundary, and target protocol. Encoding is not encryption. See the test method.