diff --git a/src/js/lz4.js b/src/js/lz4.js
index 7cd734f6e..728b0a4b3 100644
--- a/src/js/lz4.js
+++ b/src/js/lz4.js
@@ -69,7 +69,12 @@ let init = function() {
 // time elapse without the instance being used.
 
 let destroy = function() {
-    console.info('uBO: freeing lz4-block-codec instance');
+    if ( lz4CodecInstance !== undefined ) {
+        console.info(
+            'uBO: freeing lz4-block-codec instance (%s KB)',
+            lz4CodecInstance.bytesInUse() >>> 10
+        );
+    }
     lz4CodecInstance = undefined;
     textEncoder = textDecoder = undefined;
     ttlCount = 0;
@@ -118,11 +123,12 @@ let encodeValue = function(key, value) {
     outputArray[6] = (inputSize >>> 16) & 0xFF;
     outputArray[7] = (inputSize >>> 24) & 0xFF;
     console.info(
-        'uBO: [%s] compressed %d bytes into %d bytes in %s ms',
+        'uBO: [%s] compressed %d KB => %d KB (%s%%) in %s ms',
         key,
-        inputArray.byteLength,
-        outputArray.byteLength,
-        (window.performance.now() - t0).toFixed(2)
+        inputArray.byteLength >> 10,
+        outputArray.byteLength >> 10,
+        (outputArray.byteLength / inputArray.byteLength * 100).toFixed(0),
+        (window.performance.now() - t0).toFixed(1)
     );
     return outputArray;
 };
@@ -145,38 +151,39 @@ let decodeValue = function(key, inputArray) {
     }
     let value = textDecoder.decode(outputArray);
     console.info(
-        'uBO: [%s] decompressed %d bytes into %d bytes in %s ms',
+        'uBO: [%s] decompressed %d KB => %d KB (%s%%) in %s ms',
         key,
-        inputArray.byteLength,
-        outputSize,
-        (window.performance.now() - t0).toFixed(2)
+        inputArray.byteLength >>> 10,
+        outputSize >>> 10,
+        (inputArray.byteLength / outputSize * 100).toFixed(0),
+        (window.performance.now() - t0).toFixed(1)
     );
     return value;
 };
 
 return {
-    encode: function(key, data) {
-        if ( typeof data !== 'string' || data.length < 4096 ) {
-            return Promise.resolve({ key, data });
+    encode: function(key, dataIn) {
+        if ( typeof dataIn !== 'string' || dataIn.length < 4096 ) {
+            return Promise.resolve({ key, dataIn });
         }
         ttlManage(1);
         return init().then(( ) => {
             ttlManage(-1);
-            let encoded = encodeValue(key, data) || data;
-            if ( encoded instanceof Uint8Array ) {
-                encoded = new Blob([ encoded ]);
+            let dataOut = encodeValue(key, dataIn) || dataIn;
+            if ( dataOut instanceof Uint8Array ) {
+                dataOut = new Blob([ dataOut ]);
             }
-            return { key, data: encoded };
+            return { key, data: dataOut };
         });
     },
-    decode: function(key, data) {
-        if ( data instanceof Blob === false ) {
-            return Promise.resolve({ key, data });
+    decode: function(key, dataIn) {
+        if ( dataIn instanceof Blob === false ) {
+            return Promise.resolve({ key, dataIn });
         }
         ttlManage(1);
         return Promise.all([
             init(),
-            uint8ArrayFromBlob(key, data)
+            uint8ArrayFromBlob(key, dataIn)
         ]).then(results => {
             ttlManage(-1);
             let result = results[1];
diff --git a/src/lib/lz4/lz4-block-codec-js.js b/src/lib/lz4/lz4-block-codec-js.js
index d0d22b64f..c2696a714 100644
--- a/src/lib/lz4/lz4-block-codec-js.js
+++ b/src/lib/lz4/lz4-block-codec-js.js
@@ -46,13 +46,23 @@
 
 /******************************************************************************/
 
+let growOutputBuffer = function(instance, size) {
+    if (
+        instance.outputBuffer === undefined ||
+        instance.outputBuffer.byteLength < size
+    ) {
+        instance.outputBuffer = new ArrayBuffer(size + 0xFFFF & 0x7FFF0000);
+    }
+    return instance.outputBuffer;
+};
+
 let encodeBound = function(size) {
     return size > 0x7E000000 ?
         0 :
         size + size / 255 + 16;
 };
 
-let encodeBlock = function(instance, iBuf, outOffset) {
+let encodeBlock = function(instance, iBuf, oOffset) {
     let iLen = iBuf.byteLength;
     if ( iLen >= 0x7E000000 ) { throw new TypeError(); }
 
@@ -71,9 +81,11 @@ let encodeBlock = function(instance, iBuf, outOffset) {
         iBuf = new Uint8Array(iBuf);
     }
 
-    let oBuf = new Uint8Array(outOffset + encodeBound(iLen));
+    let oBuf = new Uint8Array(
+        growOutputBuffer(instance, oOffset + encodeBound(iLen))
+    );
     let iPos = 0;
-    let oPos = outOffset;
+    let oPos = oOffset;
     let anchorPos = 0;
 
     // sequence-finding loop
@@ -174,13 +186,7 @@ let encodeBlock = function(instance, iBuf, outOffset) {
 
 let decodeBlock = function(instance, iBuf, iOffset, oLen) {
     let iLen = iBuf.byteLength;
-    if (
-        instance.outputBuffer === undefined ||
-        instance.outputBuffer.byteLength < oLen
-    ) {
-        instance.outputBuffer = new ArrayBuffer(oLen + 0xFFFF & 0x7FFF0000);
-    }
-    let oBuf = new Uint8Array(instance.outputBuffer, 0, oLen);
+    let oBuf = new Uint8Array(growOutputBuffer(instance, oLen));
     let iPos = iOffset, oPos = 0;
 
     while ( iPos < iLen ) {
@@ -255,6 +261,17 @@ context.LZ4BlockJS.prototype = {
         this.outputBuffer = undefined;
     },
 
+    bytesInUse: function() {
+        let bytesInUse = 0;
+        if ( this.hashTable !== undefined ) {
+            bytesInUse += this.hashTable.byteLength;
+        }
+        if ( this.outputBuffer !== undefined ) {
+            bytesInUse += this.outputBuffer.byteLength;
+        }
+        return bytesInUse;
+    },
+
     encodeBlock: function(input, outputOffset) {
         if ( input instanceof ArrayBuffer ) {
             input = new Uint8Array(input);
diff --git a/src/lib/lz4/lz4-block-codec-wasm.js b/src/lib/lz4/lz4-block-codec-wasm.js
index fab00eda3..a13e7e6aa 100644
--- a/src/lib/lz4/lz4-block-codec-wasm.js
+++ b/src/lib/lz4/lz4-block-codec-wasm.js
@@ -125,6 +125,7 @@ context.LZ4BlockWASM = function() {
 
 context.LZ4BlockWASM.prototype = {
     flavor: 'wasm',
+
     init: function() {
         if ( this.lz4wasmInstance instanceof WebAssembly.Instance ) {
             return Promise.resolve(this.lz4wasmInstance);
@@ -158,6 +159,12 @@ context.LZ4BlockWASM.prototype = {
         this.lz4wasmInstance = undefined;
     },
 
+    bytesInUse: function() {
+        return this.lz4wasmInstance instanceof WebAssembly.Instance ?
+            this.lz4wasmInstance.exports.memory.buffer.byteLength :
+            0;
+    },
+
     encodeBlock: function(input, outputOffset) {
         if ( this.lz4wasmInstance instanceof WebAssembly.Instance === false ) {
             throw new Error('LZ4BlockWASM: not initialized');