String Utils

A static single-page text manipulation tool. Open index.html directly in Chrome or Edge — no server needed.

How to use

1. Paste text into the large textarea
2. Click a function in the sidebar
3. Fill in any parameters and press Enter (or click RUN, or press Cmd+Enter)

The output replaces the textarea content. The function list is sorted alphabetically; new functions added in the future will appear in order automatically.

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Functions

Append Before/After

Adds text to the start or end of every line.

• Position — After line or Before line
• Text — the string to add (supports escape sequences)

Change Case

Changes the case of all text.

• Case — Upper or Lower

De-dupe

Removes duplicate lines, keeping the first occurrence of each unique line. No parameters.

Delete Before/After

Deletes everything before or after the first occurrence of a search string on each line. Lines that don't contain the string are left unchanged.

• Delete — Before text or After text
• Search text — the marker string
• Delete search text — if checked, the marker string itself is also removed; otherwise it is kept

Delete Lines With/Without

Filters lines based on whether they contain a search string.

• Delete lines — With text (removes matching lines) or Without text (keeps only matching lines)
• Search text — the string to match

Find Non-ASCII

Finds all non-ASCII characters (code point > 127) in the text and returns each occurrence with up to 5 characters of surrounding context. Consecutive non-ASCII characters are grouped as a single instance; ASCII characters between them create separate instances. No parameters.

Format JSON

Reformats JSON with 2-space indentation. Uses a character-walk approach (no JSON.parse) so it degrades gracefully on invalid JSON rather than erroring. No parameters.

Normalize Columns

Pads each column so they align vertically, using a configurable delimiter.

• Delimiter — the character that separates columns (e.g. | or ,)

Replace

Replaces all occurrences of a string with another string across the entire text.

• Find — the string to search for (supports escape sequences)
• Replace with — the replacement string (supports escape sequences)

Replace from Clipboard

Replaces a search string on each line with the corresponding line from the clipboard. Line N in the textarea gets line N from the clipboard as its replacement.

• Search text — the text on each line to replace

Browser note: Requires Chrome or Edge. Firefox blocks clipboard reads from file:// pages. If Chrome prompts for permission on every use, serve the page from localhost instead (python3 -m http.server 8080) and Chrome will remember the permission permanently.

Repeat

Repeats the entire text N times, joined by newlines.

• Count — number of repetitions

Sort

Sorts lines alphabetically.

• Direction — Ascending or Descending
• Case sensitive — if unchecked, sort ignores case

Trim

Removes whitespace from each line.

• Direction — Both, Before (left), or After (right)

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Escape sequences

The Append Before/After and Replace functions support escape sequences in their text inputs:

Sequence	Meaning
\n	Newline
\t	Tab
\\	Literal backslash

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Status bar

The bar at the bottom shows:

• Ln N — current line number (1-based)
• N lines — total line count
• U+XXXX (N) — Unicode code point of the character at the cursor
• N selected — number of selected characters (replaces the code point when text is selected)

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Keyboard shortcuts

• Enter — runs the current function when focus is in the parameter panel
• Cmd+Enter / Ctrl+Enter — runs the current function from anywhere on the page