Audio Joiner - Online Concatenate Multiple Files
Upload multiple audio files and join them into a single continuous track. Add crossfade. All local.
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 audio files and join them into a single continuous track. Add crossfade. All local.
Set start and end times for a video and trim it without re-encoding. Download the clip. Pure browser.
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.
Paste your CSS and strip all `!important` declarations in one click. See a list of affected rules. Local tool.
Merge an SRT subtitle file onto a video directly in the browser. Preview and download the resulting video. All local.
Convert WebVTT subtitle files to SRT and vice versa. Handles formatting conversion and encoding. No upload, pure client-side parsing.
Take an SVG element with multiple transform attributes and merge them into a single matrix. Simplify your SVG code locally.
Apply realistic reverbs (cathedral, hall, room) to any audio using pre‑loaded impulse responses. Hear the difference instantly.
Convert .srt subtitles to .vtt format for web video players. Preserves all timestamps and formatting. Local.
Upload an audio clip and generate an animated GIF of its waveform dancing. Shareable sound snippet. Canvas magic.
Paste rich text and clean it to plain text. Normalize line endings and whitespace. Prepare for code or databases.
Load an SRT file and shift all timestamps forward or backward by milliseconds or seconds. Fix out-of-sync subtitles instantly. Download corrected file.
Reverse any short video clip and download the backward version. Fun for creative effects. Browser‑based.
Combine multiple PDF files into a single document. Drag and drop to reorder pages. All merging is done locally for confidentiality.
Load an animated GIF and adjust its frame delay to make it slower or faster. Download the modified GIF. All local.
Decode FLAC, Opus, or OGG audio files in the browser using compiled WASM libraries. Play instantly without server uploads. Keep audio private.
Turn your webcam feed into real‑time ASCII art. Adjust density and character set. Fun for streams and demos. No upload.
Drag songs into a setlist and see total duration. Perfect for planning a concert or DJ set.
See the difference between clone and slice on inline boxes that break across lines. Useful for multi‑line headings.
Paste HTML and detect elements with aria‑hidden='true' that contain focusable children. An easy a11y win to fix.
Toggle between full and reduced motion on a live animated page. See how to design for vestibular disorders. Educational.
Paste a string and get a clean, safe file name by replacing forbidden characters. Works for Windows, Mac, Linux.
Drag a slider to compare your original image with a compressed version (e.g., WebP). See the quality difference and file size savings.
Split a large CSV into smaller files by row count. Preview each chunk. No upload; streamed locally.
Convert any text into JavaScript‑style \uXXXX escape sequences and vice versa. Handles emojis. Useful for i18n development.
Select a desired emotional state (calm, energize) and get a suggested song structure with BPM range.
Shrink a PDF file size with configurable image quality and object removal. All processing stays in your browser.
Simulate adaptive bitrate logic by switching between different quality video segments. See how ABR algorithms work.
Create .srt subtitle files manually by adding lines and setting times with a simple player. Download the result. Local.