Media
Play audio files with real-time frequency visualization
audio-visualizer-playerMedia
Convert multiple audio files between different formats like MP3, WAV, FLAC, AAC, OGG, Opus with quality settings and batch processing
audio-batch-converterMedia
Edit metadata tags (artist, album, title, genre, year, track, comment) for multiple audio files at once
audio-batch-metadata-editorMedia
Normalize multiple audio files to a target peak level with consistent volume across the batch
audio-batch-normalizeMedia
Batch rename audio files using patterns, text replacement, numbering, and case conversion. Returns renamed files as a ZIP download.
audio-batch-renameMedia
Record audio directly from your microphone with real-time waveform visualization and download options
audio-recorderMedia
Schedule automatic audio recording with countdown timer and configurable duration
audio-recorder-scheduledMedia
Convert AMR (Adaptive Multi-Rate) audio files to MP3 format
amr-to-mp3Math & Numbers
Estimate academic credit hours from weekly lecture, lab, studio, term length, and contact-hour rules
credit-hour-calculatorMath & Numbers
Run chi-square goodness-of-fit or independence tests from observed counts or contingency tables
chi-square-test-calculatorMath & Numbers
Calculate exact, cumulative, and upper-tail binomial probabilities for independent Bernoulli trials
binomial-distribution-calculatorMath & Numbers
Calculate posterior probability P(A given B) using prior, likelihood, and false-positive rate
bayes-theorem-calculator