Text Viewer

Upload a file to start viewing

How It Works

Step 1: Upload large text files (logs, code, documentation, data dumps) or paste text content directly into browser with support for UTF-8, ASCII, and other encodings.
Step 2: The viewer loads file content using efficient streaming for large files (100MB+), detecting file type (log, code, plain text) and applying appropriate display settings.
Step 3: Renders text with line numbers, syntax highlighting for code files (auto-detected by extension), and monospace font for proper alignment of tabular data.
Step 4: Provides search functionality (Ctrl+F), line navigation (jump to line number), word wrap toggle, and export options for viewing and analyzing text content efficiently.

Text Viewing Examples

Example: Large Log File Viewing

Raw Text File Input

application.log (50,000 lines, 15MB)

2024-12-18 08:00:01 INFO Application started
2024-12-18 08:00:15 DEBUG Loading configuration from config.yml
2024-12-18 08:00:16 INFO Database connection established
...
[48,000 lines omitted]
...
2024-12-18 23:59:45 ERROR Database connection timeout after 30s
2024-12-18 23:59:46 WARN Retrying connection attempt 1/3
2024-12-18 23:59:50 ERROR Connection retry failed
2024-12-18 23:59:55 CRITICAL Application shutting down due to database failure

Formatted View Output

Text Viewer Display:

Line Numbers │ Content
─────────────┼────────────────────────────────────────────────────
     1       │ 2024-12-18 08:00:01 INFO Application started
     2       │ 2024-12-18 08:00:15 DEBUG Loading configuration from config.yml
     3       │ 2024-12-18 08:00:16 INFO Database connection established
     ...     │ ...
  49,998     │ 2024-12-18 23:59:45 ERROR Database connection timeout after 30s
  49,999     │ 2024-12-18 23:59:46 WARN Retrying connection attempt 1/3
  50,000     │ 2024-12-18 23:59:50 ERROR Connection retry failed
  50,001     │ 2024-12-18 23:59:55 CRITICAL Application shutting down due to database failure

File Statistics:
  Total Lines: 50,001
  File Size: 15.2 MB
  Encoding: UTF-8
  Line Endings: LF (Unix)

Search Results for "ERROR":
  Line 49,998: Database connection timeout
  Line 50,000: Connection retry failed
  Total: 2 matches

Navigation Features:
  ✓ Jump to line: 49,998 (Ctrl+G)
  ✓ Search: "ERROR" (Ctrl+F) - 2 results
  ✓ Scroll to bottom (End key)
  ✓ Word wrap: OFF (for log alignment)

Performance:
  Load Time: 1.2s (streaming)
  Memory Usage: ~30MB (virtual scrolling)
  Scroll Performance: 60 FPS (virtualized rendering)

Key Changes:

The viewer handles large files efficiently using virtual scrolling—only visible lines are rendered in DOM, preventing browser memory exhaustion. Line numbers are displayed in a fixed-width column for easy reference when discussing code or logs with team members. The viewer detects log format and applies subtle syntax highlighting: ERROR in red, WARN in yellow, INFO in blue. Search functionality (Ctrl+F) scans the entire 50,000-line file instantly using indexed search, highlighting all matches and providing navigation between results. Jump-to-line feature (Ctrl+G) allows direct navigation to specific line numbers mentioned in error reports or documentation. Word wrap can be toggled—disabled for logs to preserve column alignment, enabled for prose text. The viewer supports files too large for notepad.exe or TextEdit, which often crash on 100MB+ files. DevOps engineers use text viewers to analyze production logs without downloading to local machines, inspect database dumps for specific records, and review large configuration files. The client-side processing ensures sensitive data never leaves the browser, critical for viewing logs containing PII or credentials.

Frequently Asked Questions

How does the viewer handle extremely large files (100MB+) efficiently?

The viewer uses virtual scrolling and windowing techniques to render only visible lines, not the entire file. When you open a 100MB file with 1 million lines, only ~50 lines in the viewport are rendered in the DOM at any time. As you scroll, lines are dynamically loaded and unloaded from memory. The viewer chunks the file into 10,000-line segments, loading segments on-demand. This keeps memory usage under 200MB even for gigabyte-sized files. Search indexing happens in Web Workers to avoid blocking the UI thread—you can continue scrolling while search indexes the file. For files exceeding 500MB, the viewer offers streaming mode where only the first/last 100,000 lines are loaded initially, with middle sections loaded on-demand. This makes the viewer suitable for viewing production log files, database dumps, or data exports that would crash traditional text editors.

What character encodings and line endings does the viewer support?

The viewer auto-detects and supports multiple character encodings: UTF-8 (default), UTF-16 (LE/BE), ISO-8859-1 (Latin-1), Windows-1252, ASCII, and UTF-8 with BOM. Encoding detection analyzes the first 10KB of the file, looking for BOM markers or byte patterns. If detection fails, the viewer defaults to UTF-8 and allows manual encoding selection. Line ending formats supported include Unix (LF, \n), Windows (CRLF, \r\n), and legacy Mac (CR, \r). Mixed line endings are handled correctly, displaying each line properly regardless of terminator. The viewer shows encoding and line ending info in the status bar: "UTF-8, CRLF, 15,234 lines". This is critical for viewing files from different operating systems or legacy systems using non-UTF-8 encodings. Invalid byte sequences are displayed as replacement characters (�) with warnings.

Can the viewer detect file types and apply appropriate syntax highlighting?

Yes. The viewer detects file types using multiple methods: file extension (.js, .py, .java), shebang lines (#!/usr/bin/env python), and content analysis (looking for language-specific keywords). Supported languages include JavaScript, Python, Java, C/C++, Go, Rust, PHP, Ruby, SQL, HTML, CSS, JSON, YAML, XML, Markdown, Shell scripts, and 50+ others. Syntax highlighting uses language-specific color schemes: keywords in blue, strings in green, comments in gray, numbers in orange. The viewer also highlights special patterns: URLs (clickable links), email addresses, IP addresses, file paths, and regex patterns. For log files, it applies log-specific highlighting: ERROR in red, WARN in yellow, INFO in blue, DEBUG in gray. You can manually override language detection if auto-detection fails. This makes the viewer versatile for developers viewing code, system administrators analyzing logs, and data analysts inspecting CSV/TSV files.