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Free Β· multi-file render Β· local batch

Batch Loudness Matcher Online

Measure every track with one gated method, match the batch to a custom target or reference track, edit per-track trim, protect decoded sample peaks and export the actual aligned WAV files.

Before-and-after illustration of Batch Loudness Matcher: Mismatched track batch becomes Matched audio batch through Trim toward target.
Before → process → afterIllustration only. Audition a short current gain plan, then render the full included tracks.

UNIFORM GAIN, NOT COMPRESSION

Batch Level Targets

Measure, predict, listen, then render. Each track gets one uniform gain, not a threshold-reactive envelope. Distinguish the measured bar, predicted marker, short listening window and separate full-length output.

Before-and-after illustration of Batch Loudness Matcher: Mismatched track batch becomes Matched audio batch through Trim toward target.
Mismatched track batchTrim toward targetMatched audio batch
Illustration only, not a live meter or compressor response. The workspace compares measured level with a prediction and offers real opening-window players; full WAV/ZIP delivery requires Render.
Open the full signal breakdownBest source, processing logic, limits and three-pass listening check
  1. Start with the right material

    Evening out podcast episodes, playlist assets, sample deliveries, game dialogue or album drafts where audible level jumps matter more than merely listing measurements.

  2. Understand the transformation

    The same gated energy calculation feeds a uniform-gain plan with include, trim and optional sample-peak ceiling. Three players review one opening window; accepted decoded frames, rate and channels are preserved in the separate full render.

  3. Verify the usable result

    Measured bars versus predicted markers, real per-track Source/Result/Source-minus-Result listening, current individual PCM16 WAVs or ZIP with CSV/JSON gain manifests and offered-file receipts.

Gain ceiling and current delivery

Where this workflow stops

Not certified LUFS, a limiter or oversampled true peak. The ceiling can prevent target matching. Previews are at most ten seconds, not a full-file listening check. Browser decoding may resample; source originals stay untouched. Pending reads, edits and cancellation retire downloads; a receipt is not proof of an OS save.

THREE-PASS CHECK

Verify one current gain decision

  • Audition the selected opening as Source, Result and Source minus Result, one at a time.
  • Check include, trim, reference and ceiling; uniform gain may miss the target rather than flatten peaks.
  • Render the full tracks, reopen WAV/ZIP and compare decoded format and names with the current manifest.
One comparable measurement
Every track uses the same 400 millisecond decoded-PCM energy blocks with absolute and relative gates, clearly labeled as an estimate rather than certified LUFS.
Reference or custom target
Match all included files toward a chosen estimate or inherit one track's measured level, then add intentional per-track trim.
Real batch output
Render each included waveform at its original decoded sample rate, channels and frame count, then download WAV files individually or inside one manifest-backed ZIP.

How to match loudness across multiple audio files

  1. Choose up to 32 browser-decodable files (180 MB selected compressed input) or generate the synthetic batch. Files append only after the entire selection is accepted; the demo replaces the queue.
  2. Measure the current tracks, choose a custom estimate or measured reference, and review include, trim and the optional sample-peak ceiling. A bar is measured level; its marker is a prediction, not a moving meter.
  3. Select a track and audition Source, Result and Source minus Result, one at a time. These previews cover only the first ten seconds at most; editing or loading files stops them and retires old downloads.
  4. Render the full included tracks, then download current PCM16 WAVs or a ZIP with CSV and JSON manifests. Check the offered-file receipt, reopen the output and verify decoded frames, rate, channels and sound.

Read the gain plan before rendering

A custom target is the shared gated energy estimate; Reference inherits one measured track's level. Include controls delivery, not which track can be the reference. Trim adds an intentional offset after matching. For example, a track measured at βˆ’22 LU est. needs +6 dB to approach βˆ’16; a βˆ’1 dB trim requests +5 dB instead. A sample peak of βˆ’3 dBFS and a βˆ’1 dBFS ceiling allow only +2 dB, so the predicted result stays near βˆ’20. These illustrative values explain uniform gain, not a promise of a particular file's measurement.

Short listening check versus full-length output

The three players review the same selected opening window. Source is decoded audio, Result applies the current planned gain, and Difference is Source minus Result; silence there at zero gain is expected. Use the displayed gain and level plan to avoid mistaking a louder version for a better master. Check later passages in the full downloaded WAV too: an opening-only preview cannot reveal the loudest event elsewhere. This processor does not equalize, compress or make unrelated tracks sound identical.

Cancel, replace and retry without an old result

Cancel / stop and Escape retire pending work, players, outputs and receipts. An already-started native decode may take time to settle, but cannot add its cancelled file. Accepted tracks stay available for Measure tracks and a new render. Clear removes them; the demo explicitly replaces them. A newer file selection supersedes an older pending one. On a decode or memory refusal, no part of that selection is appended: choose fewer supported files or a shorter source and retry. Source originals are never overwritten.

Verify the delivery, not just the download button

The ZIP contains included WAVs and a matching gain manifest; excluded tracks stay excluded. WAV export preserves accepted decoded frame count, channel count and sample rate, not a compressed original byte for byte. Browser decoding can resample first. CSV quotes embedded commas and quotation marks, and prefixes formula-leading text with an apostrophe for spreadsheet safety; JSON retains literal original filenames. A receipt confirms bytes offered to the browser, not that your OS saved the file. Reopen the package and compare names and format with its manifest.

A renderer, not another album report

Album Loudness Analyzer measures release consistency and flags QC risks without changing audio. This tool goes further: it turns the shared comparison into a gain plan, renders the included tracks and packages the outputs. For one file and standard target presets, use the Loudness Normalizer.

Why a peak-safe track may miss the loudness target

The optional ceiling is deliberately transparent: it constrains uniform gain instead of compressing or limiting peaks. When a dynamic track needs more gain than its decoded sample peak allows, the console shows that the ceiling reduced requested gain and predicts the lower achieved loudness. No dynamics are hidden and no true-peak compliance is claimed.

Privacy: selected files are decoded, measured, rendered and packaged on this device. They are not uploaded to AudioWrench.

Batch Loudness Matcher: quick answer and technical limits

Quick answer: Measure a current local batch, choose a custom or reference-track estimate, audition bounded Source/Result/Difference and explicitly render full-length matched WAVs or a manifest-backed ZIP.

Best for
Evening out podcast episodes, playlist assets, sample deliveries, game dialogue or album drafts where audible level jumps matter more than merely listing measurements.
How it works
The same gated energy calculation feeds a uniform-gain plan with include, trim and optional sample-peak ceiling. Three players review one opening window; accepted decoded frames, rate and channels are preserved in the separate full render.
What you get
Measured bars versus predicted markers, real per-track Source/Result/Source-minus-Result listening, current individual PCM16 WAVs or ZIP with CSV/JSON gain manifests and offered-file receipts.

Know before you use it: Not certified LUFS, a limiter or oversampled true peak. The ceiling can prevent target matching. Previews are at most ten seconds, not a full-file listening check. Browser decoding may resample; source originals stay untouched. Pending reads, edits and cancellation retire downloads; a receipt is not proof of an OS save.

Privacy: Selected audio is processed in this browser and is not uploaded to AudioWrench. Normal page assets can still be requested as described in the privacy notice. Privacy details β†’

FAQ

How is this different from Album Loudness Analyzer?
Album Loudness Analyzer is an analysis-only release QC workspace. Batch Loudness Matcher uses a consistent estimate to calculate and render per-track gain, then exports the changed WAV files.
How is this different from Loudness Normalizer?
Loudness Normalizer handles one source file. This matcher keeps a bounded multi-track queue, can inherit a reference track level, supports per-track include and trim, and packages the complete batch.
Are these certified LUFS measurements?
No. Values are a consistent gated decoded-PCM energy estimate using 400 millisecond blocks, an absolute minus 70 gate and a relative minus 10 gate. There is no certified K-weighting or compliance claim.
What does the transparent peak ceiling do?
It reduces uniform gain for the whole track when the requested match would exceed the chosen decoded sample peak. It is not a limiter, does not alter dynamics, does not measure oversampled true peak and may prevent the loudness target from being reached.
Does batch export preserve each source format?
It preserves each decoded track's sample rate, channel count, frame count and duration, then exports a new PCM16 WAV. A compressed input is not copied bit for bit, and browser decoding may resample it first.
Are my audio files uploaded?
No. Decoding, measurement, gain rendering, WAV encoding and ZIP packaging run in this browser on your device.

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