User manual

A reference for comparing, reviewing, and keeping both versions.

Start with two versions

1. Paste or type into Original and Modified, or use each input's Open file action.
2. Choose Compare texts. Exact case and spacing are compared initially.
3. Review the removed and added lines. Word highlights narrow your attention inside each change group.
4. Copy a source or download a comparison report before leaving.

One empty side is valid: the result shows everything added or removed. Whitespace-only text is also valid. With both inputs empty, the workspace waits for text. Try an example supplies a two-line meeting note with Tuesday changed to Thursday.

Understand the comparison

Original is the reference; Modified is the version compared against it. A replaced line counts as one removed line and one added line. Adjacent additions/removals form a change group; an unchanged line separates groups. This is token alignment, not a semantic assessment. Repeated lines can have multiple reasonable alignments.

Line records retain their LF terminator. a\n is one record, and a\n\n is two. There is no phantom record after a final newline. A line that lacks a final newline has a visible marker. Soft wrapping inside an editor or result does not create a new logical line.

Word detail groups Unicode letters, numbers and combining marks, while spaces, punctuation and other code points remain separate tokens. This is a visual aid rather than a dictionary word count. It does not detect moved paragraphs, meaning changes, plagiarism, or originality.

Line endings and file signatures

The working comparison maps Windows CRLF and lone CR line endings to LF. Final-newline presence remains significant. Importing a leading UTF-8 signature removes that signature and announces it. Pasted BOM characters are retained. Reports contain prepared LF text, so they are not a byte-identical file comparison or an original-encoding backup.

Optional case and spacing rules

Ignore letter case applies locale-independent lowercasing. It is not complete Unicode case folding: for example, Straße and STRASSE may still differ. No Unicode normalization is applied.

Ignore extra spaces and tabs trims ASCII spaces/tabs at line edges and reduces internal runs to one space. Blank-record presence, ordinary word separators, non-breaking spaces and other Unicode spacing remain meaningful. alpha beta still differs from alphabeta.

Options change comparison keys, not your source strings. Results show which rules were used. Identical text means the prepared strings match literally. No differences with these options means they align under the selected rules; their appearance can differ. Side-by-side results retain both values, and Unified identifies the original value when an ignored variation exists.

Views and navigation

Desktop starts Side by side. Narrow screens start Unified, which marks removed and added rows with minus and plus signs. The view buttons let you choose either layout. Hide unchanged lines retains three context records around changes; expand a collapsed section to inspect it. Show word changes only changes highlighting.

Previous change and Next change move among groups. Long results are paged in at most 200 displayed records at a time. Change navigation opens the relevant page. These display choices do not alter counts or the complete exported comparison.

Files and limits

Open one .txt or .md file per side, encoded as UTF-8, up to 1 MiB (1,048,576 bytes). Each decoded source must also fit 100,000 UTF-16 input units and 10,000 line records. A visible emoji or combined character can use several units. Invalid encoding, an unsupported extension, or an exceeded limit leaves the previously accepted input intact. Content is treated as plain text, even when it contains HTML or code.

Comparison runs in a browser worker and has a time/edit budget. Cancel comparison stops it while retaining both inputs. Very large or highly different inputs can reach a comparison limit; compare a smaller section. If the worker is unavailable, use a current browser.

Word detail is limited separately: groups above 20,000 combined input units or 4,000 detail tokens, or those unable to finish promptly, use a clearly labeled line comparison. That fallback does not discard line differences. Reports identify incomplete detail groups.

Changes, Clear, and Undo

Editing a source or an ignore rule invalidates the previous result. Compare again before exporting. An obsolete worker result cannot replace a newer input state. Swap reverses the two sources. Clear removes both inputs. Undo restores the last six Clear, Swap, example or file-replacement actions in page memory; typing undo belongs to the browser. Restored inputs need a new comparison.

Replacing entered text with a file or example asks first. Internal links offer to keep the current workspace open in a new tab. Closing, reloading or leaving can lose work. Browser back/forward restoration is not a reliable save feature.

Copy and reports

Copy original text and Copy modified text copy the accepted source on that side after your click. Copy report copies a plain-text comparison. If clipboard permission fails, the app selects the text in a dialog for your device's manual copy action.

Download report offers visual HTML, Markdown, TXT and JSON. All include both prepared texts and the full comparison, even when the visible result is paged or unchanged lines are hidden. Reports include versions, active rules, preparation notices, counts and word-detail completeness. JSON is a data report, not a restorable session. Reports use UTF-8, LF and fixed safe filenames, with a 2 MiB final-byte limit. An oversized report is rejected without discarding your work. Downloaded HTML has no scripts or remote resources; you can open it and use your browser's print action.

Keyboard, mobile, and appearance

Use Tab to move between controls and Enter/Space to activate buttons. Result navigation moves focus to the change group. Dialogs offer cancellation; Escape dismisses them. Labels, plus/minus signs and text notices supplement color. Narrow screens keep controls inside the page and wrap long strings.

System, Light and Dark share the existing Mycelgrid appearance preference. Change it here or in the platform footer. Each app keeps its own palette. Appearance can be remembered in this browser; input text, files, options and reports are not automatically saved. When storage is unavailable, theme choice lasts only on the current page.

Read the comparison guide for invisible-character and alignment examples. Report a reproducible issue using deidentified sample text.