Rúmil Help

A complete list of all available text transformation commands.

About

Rúmil is a text manipulation tool for everyday data wrangling. Paste in database output, log files, API responses, or any raw text and quickly transform it into the format you need — whether that's a spreadsheet-ready CSV, a converted data format like JSON to XML, or just cleaned-up text you can share with colleagues. It is not a code editor or IDE; there is no syntax highlighting or project management. Instead, it focuses on doing one thing well: reshaping text fast.

Named after Rúmil of Tirion, the Elf who invented the first writing system in Tolkien's legendarium.

Keyboard Shortcuts

Action	Mac	Windows/Linux
Open Command Palette	`⌘K`	`Ctrl+K`
Open Settings	`⌘,`	`Ctrl+,`
Open File	`⌘O`	`Ctrl+O`
Save / Download	`⌘S`	`Ctrl+S`
Find and Replace	`⌘F` `⌘H`	`Ctrl+F` `Ctrl+H`
Add Cursor	`Option + Click`	`Alt + Click`
Select Next Occurrence	`Ctrl+G`	`Alt+J`
Go to Line	`⌘L`	`Ctrl+G`
Select All Occurrences	`Ctrl+⌘G`	`Ctrl+Alt+Shift+J`
Indent Line(s)	`Tab`	`Tab`
Unindent Line(s)	`Shift+Tab`	`Shift+Tab`
Move Line(s) Up	`Option+Shift+↑`	`Alt+Shift+↑`
Move Line(s) Down	`Option+Shift+↓`	`Alt+Shift+↓`
Duplicate Line / Selection	`⌃⌥C`	`Ctrl+Alt+C`
Toggle Split Editor	`⌘\`	`Ctrl+\`
Switch Panel Focus	`⌘←/→` `⌘↑/↓`	`Ctrl+←/→` `Ctrl+↑/↓`
Close Focused Panel	`⌃W`	`Ctrl+W`

Using the Command Palette

Press ⌘K (Mac) or Ctrl+K (Windows/Linux) to open the command palette. Type to search for commands, use arrow keys to navigate, and press Enter to execute.

remove|

Remove Whitespace (ignore newlines)

Remove spaces and tabs but keep line breaks

Remove Whitespace (include newlines)

Remove all whitespace including line breaks

↑↓ Navigate↵ SelectEsc Close

Commands

Case Transforms

Uppercase

Convert all letters to uppercase

hello world→HELLO WORLD

Lowercase

Convert all letters to lowercase

HELLO WORLD→hello world

Capitalize

Capitalize the first letter of each word

hello world→Hello World

Decapitalize

Lowercase the first letter of each word

Hello World→hello world

Titleize

Convert text to Title Case

hello world→Hello World

Title Case (AP Style)

Title case following AP style (capitalizes 4+ letter prepositions)

running through the forest→Running Through the Forest

Title Case (Chicago Style)

Title case following Chicago style (lowercases all prepositions)

running through the forest→Running through the Forest

Sentence Case

Capitalize only the first letter of the text

hello world→Hello world

Camelize

Convert text to camelCase format

hello world→helloWorld

Pascal Case

Convert text to PascalCase (UpperCamelCase)

hello world→HelloWorld

Snake Case

Convert text to snake_case (underscore-separated lowercase)

hello world→hello_world

Screaming Snake Case

Convert text to SCREAMING_SNAKE_CASE (uppercase with underscores)

hello world→HELLO_WORLD

Dasherize

Convert text to kebab-case (hyphen-separated lowercase)

hello world→hello-world

Dot Case

Convert text to dot.case (dot-separated lowercase)

hello world→hello.world

Swap Case

Swap uppercase and lowercase letters

Hello World→hELLO wORLD

Alternating Case

Alternate case starting with lowercase

hello world→hElLo WoRlD

Inverse Alternating Case

Alternate case starting with uppercase

hello world→HeLlO wOrLd

Random Case

Randomly change the case of each letter

Output varies each time

hello world→hElLo WoRLd

Humanize

Convert machine-readable text to human-readable format

hello_world→Hello world

Slugify

Convert text to URL-friendly slug format

Hello World!→hello-world

Text Operations

Clean

Remove extra whitespace, leaving single spaces between words

hello world →hello world

Clean Diacritics

Remove accents and diacritical marks from characters

café résumé→cafe resume

Remove Whitespace (ignore newlines)

Remove spaces and tabs but keep line breaks

hello world→helloworld

Remove Whitespace (include newlines)

Remove all whitespace including line breaks

hello world→helloworld

Reverse

Reverse the order of characters

hello→olleh

Swap Quotes

Swap single and double quotes

"hello" 'world'→'hello' "world"

Quote

Wrap text with double quotes

hello→"hello"

Unquote

Remove surrounding quotes (supports single, double, and smart quotes)

"hello"→hello

Chop into Groups

Split text into groups of N characters (comma-separated)

Requires input: number of characters per group

hello→hel,lo

Repeat

Repeat the text N times

Requires input: number of repetitions (example shows 3)

ab→ababab

Truncate

Truncate text to N characters, adding ellipsis

Requires input: maximum length (example shows 8)

hello world→hello...

Prune

Truncate text at word boundary, adding ellipsis

Requires input: maximum length (example shows 12)

hello world foo→hello...

Wrap With...

Wrap text with characters (auto-matches pairs like parentheses)

Requires input: opening character (e.g., ( [ { " ' **)

hello→(hello)

Unwrap

Remove surrounding characters (auto-detects pairs)

(hello)→hello

Pad Left

Pad text on the left to reach target length

Requires input: target length and optional padding character (e.g., '5, 0')

42→00042

Pad Right

Pad text on the right to reach target length

Requires input: target length and optional padding character (e.g., '5')

hi→hi

Center

Center text within a target width by padding both sides

Requires input: target width and optional padding character (e.g., '11' or '11, -')

hello→ hello

Extract Numbers

Extract all numbers from text, one per line

Order 123 costs $45.99→123 45.99

Remove Numbers

Remove all numeric characters from text

Order 123 costs $45.99→Order costs $.

Extract Emails

Extract all email addresses from text, one per line

Contact john@example.com or jane@test.org→john@example.com jane@test.org

Extract URLs

Extract all URLs from text, one per line

Visit https://example.com or https://test.org→https://example.com https://test.org

Remove Non-Alphanumeric

Keep only letters and numbers, remove everything else

Hello, World! 123→HelloWorld123

Add Prefix

Add text to the beginning

Requires input: the prefix to add (example shows 'Hello ')

world→Hello world

Add Suffix

Add text to the end

Requires input: the suffix to add (example shows ' world')

Hello→Hello world

Number Operations

Increment All Numbers

Add 1 to all integers in the text

item1 count5→item2 count6

Decrement All Numbers

Subtract 1 from all integers in the text

item2 count6→item1 count5

Increment All Floats

Add 1 to all numbers (including decimals) in the text

price 9.99→price 10.99

Decrement All Floats

Subtract 1 from all numbers (including decimals) in the text

price 10.99→price 9.99

Create Sequence

Create a sequence from numbers, starting with the first number found

1 1 1 1 1 1→1 2 3 4 5 6

Line Operations

Sort Lines (A-Z)

Sort lines alphabetically ascending (case-insensitive)

Banana apple Cherry→apple Banana Cherry

Sort Lines (Z-A)

Sort lines alphabetically descending (case-insensitive)

apple Banana Cherry→Cherry Banana apple

Sort Lines (A-Z, Case-Sensitive)

Sort lines alphabetically ascending (case-sensitive)

banana Apple cherry→Apple banana cherry

Sort Lines (Z-A, Case-Sensitive)

Sort lines alphabetically descending (case-sensitive)

Apple banana cherry→cherry banana Apple

Sort Lines (Numeric)

Sort lines by numeric value

item 10 item 2 item 1→item 1 item 2 item 10

Reverse Lines

Reverse the order of lines (not characters)

first second third→third second first

Shuffle Lines

Randomly reorder lines

Output varies each time

a b c→c a b

Remove Duplicate Lines

Keep only unique lines (ignores whitespace differences)

apple banana apple→apple banana

Remove Empty Lines

Delete blank lines from text

hello world→hello world

Trim Lines

Remove leading/trailing whitespace from each line

hello world →hello world

Join Lines

Join multiple lines into one with a separator

Requires input: separator (example shows ', ')

apple banana cherry→apple, banana, cherry

Split to Lines

Split text by delimiter into separate lines

Requires input: delimiter (example shows ', ')

apple, banana, cherry→apple banana cherry

Number Lines

Add line numbers as a prefix to each line

hello world→1. hello 2. world

Developer Tools

JSON Format

Pretty print JSON with indentation

{"name":"John","age":30}→{ "name": "John", "age": 30 }

JSON Minify

Compact JSON to a single line

{ "name": "John" }→{"name":"John"}

JSON to YAML

Convert JSON to YAML format

{"name":"John","age":30}→name: John age: 30

JSON to JS Object

Convert JSON to JavaScript object literal by removing quotes from valid identifier keys

{"name": "John"}→{name: "John"}

JS Object to JSON

Convert JavaScript object literal to valid JSON by adding quotes to keys

{name: "John"}→{"name": "John"}

JSON to XML

Convert JSON to XML format

{"name":"John","age":30}→<root> <name>John</name> <age>30</age> </root>

JS Object to YAML

Convert JavaScript object literal to YAML format

{name: "John", age: 30}→name: John age: 30

JS Object to XML

Convert JavaScript object literal to XML format

{name: "John", age: 30}→<root> <name>John</name> <age>30</age> </root>

YAML to JSON

Convert YAML to JSON format

YAML to JS Object

Convert YAML to JavaScript object literal

YAML to XML

Convert YAML to XML format

XML to JSON

Convert XML to JSON format

<root><name>John</name><age>30</age></root>→{"name":"John","age":"30"}

XML to YAML

Convert XML to YAML format

<root><name>John</name><age>30</age></root>→name: John age: 30

CSV to JSON

Convert CSV data to a JSON array of objects (first row as headers)

name,age Alice,30 Bob,25→[{"name":"Alice","age":30},{"name":"Bob","age":25}]

JSON to CSV

Convert a JSON array of objects to CSV (keys become headers)

[{"name":"Alice","age":30},{"name":"Bob","age":25}]→name,age Alice,30 Bob,25

XML Format

Pretty print XML with indentation

XML Minify

Compact XML to a single line

CSS Format

Pretty print CSS with indentation

.class{color:red;margin:0}→.class { color: red; margin: 0; }

CSS Minify

Compact CSS to a single line

.class { color: red; }→.class{color:red}

CSS-in-JS to CSS

Convert CSS-in-JS syntax to plain CSS

backgroundColor: "red",→background-color: red;

CSS to CSS-in-JS

Convert plain CSS to CSS-in-JS syntax

background-color: red;→backgroundColor: "red",

Hex to RGB

Convert hex colour codes (#RGB, #RRGGBB, #RRGGBBAA) to rgb()/rgba()

#ff5733→rgb(255, 87, 51)

RGB to Hex

Convert rgb()/rgba() colour values to hex codes

rgb(255, 87, 51)→#ff5733

Hex to HSL

Convert hex colour codes to hsl()/hsla()

#ff0000→hsl(0, 100%, 50%)

HSL to Hex

Convert hsl()/hsla() colour values to hex codes

hsl(0, 100%, 50%)→#ff0000

RGB to HSL

Convert rgb()/rgba() colour values to hsl()/hsla()

rgb(255, 0, 0)→hsl(0, 100%, 50%)

HSL to RGB

Convert hsl()/hsla() colour values to rgb()/rgba()

hsl(0, 100%, 50%)→rgb(255, 0, 0)

Escape String

Escape quotes and special characters for string literals

Hello "World"→Hello \"World\"

Unescape String

Convert escape sequences back to characters

Hello \"World\"→Hello "World"

Table to CSV

Convert ASCII table format (with | separators) to CSV

col1 | col2 -----+----- 1 | a→col1,col2 1,a

Table to TSV

Convert ASCII table format (with | separators) to TSV (tab-separated)

col1 | col2 -----+----- 1 | a→col1\tcol2 1\ta

Generate Placeholder Text

Generate random placeholder text by words, paragraphs, or bytes

5 words→xkf qwerty abc jlmnop z

Generate Lorem Ipsum

Generate classic Lorem Ipsum text by words, paragraphs, or bytes

5 words→Lorem ipsum dolor sit amet

Encoding/Decoding

Base64 Encode

Encode text to Base64 format

Hello World→SGVsbG8gV29ybGQ=

Base64 Decode

Decode Base64 back to text

SGVsbG8gV29ybGQ=→Hello World

URL Encode

Percent-encode special characters for URLs

hello world→hello%20world

URL Decode

Decode percent-encoded URLs

hello%20world→hello world

HTML Entity Encode

Convert special characters to HTML entities

HTML Entity Decode

Convert HTML entities back to characters

Unicode Escape

Convert non-ASCII characters to \uXXXX format

café→caf\u00e9

Unicode Unescape

Convert \uXXXX sequences back to characters

caf\u00e9→café

Hash/Checksum

SHA-256 Hash

Generate SHA-256 hash of text (replaces selection with hash)

hello→2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

Character Count

Show detailed character statistics (characters, words, lines, paragraphs, bytes)

hello world→Characters: 11 Characters (no spaces): 10 Words: 2 Lines: 1 Paragraphs: 1 Bytes: 11

Multi-Cursor

Add Cursor to Line Ends

Add a cursor at the end of each selected line for simultaneous editing

| represents cursor positions

aaa bbb ccc→aaa| bbb| ccc|

Add Cursor to Line Starts

Add a cursor at the start of each selected line for simultaneous editing

| represents cursor positions

aaa bbb ccc→|aaa |bbb |ccc

Split Selection into Lines

Create a separate selection for each line in the current selection

[] represents selection ranges

[aaa bbb ccc]→[aaa] [bbb] [ccc]

Date/Time

Insert Date

Insert the current date in ISO 8601 format at the cursor position

(cursor)→2026-02-07

Insert Time

Insert the current time in 24-hour format at the cursor position

(cursor)→01:18:41

Insert Date-Time

Insert the current date and time in ISO 8601 format at the cursor position

(cursor)→2026-02-07T01:18:41

Customize Date/Time Format

Open a format builder to customize the output of Insert Date, Insert Time, and Insert Date-Time. Choose from presets or build your own format with year, month, day, hour, minute, second, AM/PM, and separator pieces.

(command palette)→Opens format builder modal

Insert UUID

Generate a random UUID (v4) and insert it at the cursor position

Output varies each time

(cursor)→550e8400-e29b-41d4-a716-446655440000

Theme Names

The themes are named after Elven loremasters and scribes from Tolkien's legendarium:

Rúmil — The Elf of Tirion who invented the first writing system (the Sarati) in Aman.

Daeron — The minstrel and loremaster of King Thingol in Doriath, who invented the Cirth (runic alphabet).

Erestor — Chief counselor of Elrond's household in Rivendell, present at the Council of Elrond.

Pengolodh — The great loremaster of Gondolin who compiled the Annals of Beleriand and other histories.

Fëanor — The greatest of the Noldor, creator of the Silmarils and inventor of the Tengwar script.