Removing meaningful structure
Blank rows often separate paragraphs, headings, or code sections. Use Collapse runs when one visible separator should remain.
Remove Empty Lines | Remove or Collapse Blank Rows
TextRuns in Your Browser (No Uploads)
Remove every empty or whitespace-only line, or collapse each consecutive blank run to one separator. Preserve uniform LF, CRLF, or CR endings, inspect exact counts, and process bounded text in a browser Worker.
What to do next
Continue with a related workflow or open the next tool that usually follows this task.
Workflow guide
Test JavaScript regex against real multiline text
A multiline regex review needs the original line structure, a known pattern representation, deliberate flags, exact match and capture ranges, and a failing near-match. Run the native expression in an isolated worker, interpret offsets as UTF-16, and verify the final pattern again in the destination runtime before replacement or deployment.
OpenRelated toolLine Ending Detector for CRLF, LF, and Mixed Text Files
Count original CRLF, LF, CR, and Unicode line separators in a local file.
OpenRelated toolJavaScript Regex Tester with Worker Timeout and Capture Ranges
Test bounded JavaScript regex in a worker with capture ranges, highlights, and a one-second timeout.
OpenRelated toolRemove Duplicate Lines | Keep First Occurrences
Keep first occurrences, compare case or trimmed keys, and optionally sort unique lines locally.
OpenHow to Use This Tool
Save the original before changing blank rows, especially when paragraph spacing, code indentation, or terminal line endings carry meaning.
Load prose or row-oriented text whose empty separators need review, either by pasting it or selecting a supported local text file within the shown limits.
Choose Remove all for one-record-per-line data or Collapse runs to retain one separator per blank group.
Leave Trim surviving lines off unless leading and trailing whitespace should be removed from real content.
Run the Worker and compare source, output, blank, and removed line counts.
Read any trimming or mixed-line-ending warning, inspect the result, then copy or download it.
When to Use This Tool
Log and stack-trace cleanup
Delete empty records from copied server logs while preserving message order and the file's uniform line-ending style.
List preparation
Prepare one-item-per-line IDs, URLs, hostnames, or labels before deduplication or import.
Paragraph gap normalization
Collapse repeated gaps in meeting notes or copied prose while keeping one paragraph separator.
Copied text repair
Remove whitespace-only rows introduced by spreadsheet, PDF, or email copy and paste.
Line-ending-aware cleanup
Inspect whether CRLF, LF, or mixed endings will be retained or normalized before a script or repository import.
Common Mistakes
Trimming indentation by accident
Trim surviving lines removes leading whitespace from nonblank lines. Leave it off for Python, YAML, nested code, and aligned text.
Assuming every invisible character is blank
JavaScript whitespace is classified with trim(), but zero-width characters such as U+200B are not whitespace and remain visible in the counts as nonblank content.
Skipping the line-ending notice
Uniform LF, CRLF, or CR is preserved. Mixed input is normalized to the most frequent source style, so byte-sensitive files need review.
Exporting an all-blank result without review
Remove all returns an empty result when every source row is blank. Check the source and summary before replacing a file or field.
Examples
Remove all blank log rows
Remove empty and whitespace-only rows from a log while keeping the final line ending.
Input
ERROR start
request failed
retry queued
Output
ERROR start
request failed
retry queued
Collapse repeated paragraph gaps
Collapse multiple paragraph gaps to one empty row without joining the paragraphs together.
Input
Title
Paragraph one
Paragraph twoOutput
Title
Paragraph one
Paragraph twoBlank classification and output contract
Blank-row scanning recognizes LF, CRLF, and CR. A separator at end-of-file records the final ending style but does not manufacture another source row to remove.
A line is blank when String.trim() returns an empty string. Unicode whitespace covered by trim() is blank, while zero-width format characters remain content.
Remove all omits every blank row. Collapse runs emits one empty row for each consecutive blank group and normalizes whitespace-only separators to an empty row.
Surviving line content is unchanged by default. Optional trimming removes leading and trailing whitespace and reports how many nonblank lines changed.
Uniform line endings and a terminal ending are preserved when output remains. Mixed endings use the most frequent source style, with first appearance as the tie-breaker.
Processing is O(n), capped at 1,048,576 UTF-8 bytes and 200,000 lines, and runs in a module Worker with a three-second deadline without sending source text to analytics.
Frequently Asked Questions
What counts as a blank line?
A row is blank when JavaScript trim() leaves no characters. This includes ordinary spaces, tabs, non-breaking spaces, and many Unicode whitespace characters.
How do the two blank-line modes differ?
Remove all deletes every blank row. Collapse runs retains one empty row for each consecutive group, which is safer for prose and sectioned notes.
Does the tool change text on nonblank lines?
Only when you enable Trim surviving lines. That option removes both leading and trailing whitespace from nonblank lines and can alter code indentation.
What happens to line endings?
A single LF, CRLF, or CR convention survives cleanup, as does its terminal ending when content remains. With mixed separators, the most frequent one wins and first occurrence resolves equal counts.
Are zero-width characters treated as blank?
No. Zero-width space and similar format characters are not removed by trim(), so a row containing one is treated as nonblank. Use the zero-width character tool when needed.
Does it reorder or normalize my text?
No. The parser preserves source order and applies no Unicode normalization. It only removes or collapses blank rows and optionally trims surviving lines.
What are the size and privacy limits?
Blank-line cleanup accepts at most 1,048,576 UTF-8 bytes across 200,000 source lines. Processing runs in a browser Worker with a three-second deadline, and analytics receives counts and options rather than text.
How This Tool Was Verified
Maintained and tested by SimpleWebUtilsReviewed
Method: For the Remove Empty Lines review, we preserved the source shown in “Collapse repeated gaps in release notes” and completed “Identify the text structure” and “Run the bounded Worker”. The produced output was compared literally where possible, with “Deleting every paragraph separator” and “Trimming indentation casually” checked against the linked failure evidence.
Expected result: Collapse-runs mode reduced four blank lines in two runs to two separators, preserved all three release-note lines, and left leading and trailing content untouched with trimming disabled.
Open the tested workflowRelated workflow guides
Use these focused guides when you need a practical workflow before opening the tool.
Workflow guide
Test JavaScript regex against real multiline text
A multiline regex review needs the original line structure, a known pattern representation, deliberate flags, exact match and capture ranges, and a failing near-match. Run the native expression in an isolated worker, interpret offsets as UTF-16, and verify the final pattern again in the destination runtime before replacement or deployment.
Workflow guideDeduplicate lines from lists and logs without losing order
A practical workflow for turning repeated one-item-per-line data into an auditable unique list while preserving the first useful occurrence.
Workflow guideSort unique lines naturally before an import
A review-first workflow for producing a unique, naturally ordered list of IDs, names, URLs, tags, or labels without confusing sorting with normalization.
Workflow guideRemove blank lines from pasted text without losing structure
A reviewable workflow for cleaning empty and whitespace-only rows while preserving the structure, order, and line-ending details that still matter.
Workflow guideRemove line numbers from copied text without deleting real values
Use this workflow when code viewers, PDFs, transcripts, legal documents, or exported notes add numbers at the start of copied lines. Keep the source, distinguish marked numbering from ambiguous plain integers, compare cleanup evidence, and validate the result before reuse.
Workflow guideReplace text safely with regex captures and boundaries
A safe bulk-replacement workflow starts with an untouched source and the narrowest matching rule. It proves patterns separately, makes every flag and dollar token explicit, reviews boundary and zero-width diagnostics, compares the exact output, and tests the destination instead of treating a replacement count as correctness.
Workflow guideAdd fixed labels and delimiters to copied lines safely
Use this workflow for a plain list copied from a spreadsheet, report, log, or editor when every row needs the same label, marker, wrapper, or delimiter. It keeps line boundaries exact and separates bulk text insertion from JSON, CSV, SQL, shell, or HTML validation.
Related Tools
Continue with another maintained workflow
Line Ending Detector for CRLF, LF, and Mixed Text Files
Count original CRLF, LF, CR, and Unicode line separators in a local file.
Text
JavaScript Regex Tester with Worker Timeout and Capture Ranges
Test bounded JavaScript regex in a worker with capture ranges, highlights, and a one-second timeout.
Text
Remove Duplicate Lines | Keep First Occurrences
Keep first occurrences, compare case or trimmed keys, and optionally sort unique lines locally.
Text
Remove Line Numbers Without Damaging Code or Inline Values
Remove line-start numbering while preserving inline values, indentation, and exact line endings.
Text
Find and Replace Text | Literal and Regex Replacement
Replace literal or regex matches with Unicode boundaries, capture tokens, exact counts, and Worker limits.
Text
Word Counter | Words, Graphemes, Code Points and UTF-8 Bytes
Count word-like segments, graphemes, code points, UTF-16 units, UTF-8 bytes, lines and reading time locally.
Text