Text File Merger - Online Combine Multiple TXT
Upload multiple text files and concatenate them into one, with optional separators. No upload; processed instantly.
UD5 Toolkit
Replace, remove, or extract audio tracks from your videos — all processed locally in your browser for complete privacy.
Upload Video File
MP4, WebM, MOV, AVI, MKV — up to 500 MB
Upload New Audio Track
MP3, WAV, AAC, OGG, FLAC — up to 200 MB
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Upload multiple text files and concatenate them into one, with optional separators. No upload; processed instantly.
Convert subtitle files between SRT and WebVTT formats. Also shift all timestamps forward/backward. Works locally.
Convert WebVTT subtitle files to SRT and vice versa. Handles formatting conversion and encoding. No upload, pure client-side parsing.
Merge an SRT subtitle file onto a video directly in the browser. Preview and download the resulting video. All local.
Load an SRT file and shift all timestamps forward or backward by milliseconds or seconds. Fix out-of-sync subtitles instantly. Download corrected file.
Load an animated GIF and adjust its frame delay to make it slower or faster. Download the modified GIF. All local.
Drag songs into a setlist and see total duration. Perfect for planning a concert or DJ set.
Paste prose and reformat so that each sentence starts on a new line. Helps with version control diffs.
Play any video at a custom rate (0.25x to 4x) without audio pitch change. Save the playback speed as a link. Local.
Play any video at 0.25x to 4x speed. Save the modified speed as a new file. Perfect for analysis or fun.
Paste a string and get a clean, safe file name by replacing forbidden characters. Works for Windows, Mac, Linux.
Load a GIF and adjust playback speed. Save modified GIF. Pure client-side processing.
Transform regular text into the mocking SpongeBob‑style alternating case. Copy and paste for hilarious effect.
Convert any phrase into the NATO phonetic alphabet (Alpha, Bravo, Charlie…). Copy or hear pronunciation. Useful for call centers.
Shrink a PDF file size with configurable image quality and object removal. All processing stays in your browser.
Convert any text into JavaScript‑style \uXXXX escape sequences and vice versa. Handles emojis. Useful for i18n development.
Convert nested JSON translation files into a flat CSV table for translators. Also reverse back. Local only.
Turn a cardinal number (23) into its ordinal form (23rd). Supports large numbers. Simple and quick.
Check English spelling and get suggestions using the browser's built-in dictionary. Highlight errors instantly. No data leaves your machine.
Format a list of Q&A pairs and export as a CSV ready for Anki import. Simple line‑based template. Local.
Shows each character's 7‑bit or 8‑bit binary representation. Includes space separation. For learning binary encoding.
Paste a list of names and split them into a specified number of random teams. Perfect for sports and classrooms.
Enter a regular expression and see a visual railroad diagram explaining the pattern. Learn and debug regex.
Watch classic sorting algorithms step through a randomized bar chart. Adjust speed and array size. Great for learning algorithm efficiency.
Type or paste Korean Hangul and see the revised romanization. Also works backwards for basic words. Study aid.
Paste text and detect its language (70+ languages) using a simple character n-gram model implemented in JavaScript. No server communication.
Type a simple sentence and see a rudimentary Reed‑Kellogg diagram. Educational.
Paste two texts and see cosine and Jaccard similarity scores. Understand how close two documents are. All local math.
Convert plain text into leet (1337) speak and decode it back. Great for gamer tags and online culture. Fun, free, and local.
Create a weighed pros and cons list with a score. Help make tough decisions. Data saved locally.