diff --git a/lib/backends/webgl/glsl-coordinate-lib.ts b/lib/backends/webgl/glsl-coordinate-lib.ts
index b0adbe61..f971e0bf 100644
--- a/lib/backends/webgl/glsl-coordinate-lib.ts
+++ b/lib/backends/webgl/glsl-coordinate-lib.ts
@@ -89,7 +89,7 @@ export class CoordsGlslLib extends GlslLib {
    * Generates code for packed output sampler.
    */
   protected getPackedOutputSamplingSnippet(outputLayout: TextureLayout): {[name: string]: GlslLibRoutine;} {
-    const outShape = outputLayout.shape;
+    const outShape = outputLayout.unpackedShape;
     const outTexShape = [outputLayout.width, outputLayout.height];
     const result: {[name: string]: GlslLibRoutine} = {};
     const funcName = 'getOutputCoords';
@@ -231,7 +231,7 @@ export class CoordsGlslLib extends GlslLib {
 
     const packedTexShape = texShape;
     // texels needed to accommodate a logical row
-    const texelsInLogicalRow = shape[1];
+    const texelsInLogicalRow = Math.ceil(shape[1] / 2);
 
     /**
      * getOutputCoords
@@ -264,8 +264,9 @@ export class CoordsGlslLib extends GlslLib {
    */
   protected getOutputPacked3DCoords(shape: [number, number, number], texShape: [number, number]): GlslLibRoutine {
     const packedTexShape = [texShape[0], texShape[1]];
-    const texelsInLogicalRow = shape[2];
-    const texelsInBatch = texelsInLogicalRow * shape[1];
+    const texelsInLogicalRow = Math.ceil(shape[2] / 2);
+
+    const texelsInBatch = texelsInLogicalRow * Math.ceil(shape[1] / 2);
     const source = `
         ivec3 getOutputCoords() {
           ivec2 resTexRC = ivec2(TexCoords.xy *
@@ -291,8 +292,8 @@ export class CoordsGlslLib extends GlslLib {
   protected getOutputPackedNDCoords(shape: ReadonlyArray<number>, texShape: [number, number]): GlslLibRoutine {
     const packedTexShape = [texShape[0], texShape[1]];
 
-    const texelsInLogicalRow = shape[shape.length - 1];
-    const texelsInBatch = texelsInLogicalRow * shape[shape.length - 2];
+    const texelsInLogicalRow = Math.ceil(shape[shape.length - 1] / 2);
+    const texelsInBatch = texelsInLogicalRow * Math.ceil(shape[shape.length - 2] / 2);
     let texelsInBatchN = texelsInBatch;
     let batches = ``;
     let coords = 'b, r, c';
diff --git a/lib/backends/webgl/ops/concat_packed.ts b/lib/backends/webgl/ops/concat_packed.ts
index e3453879..16c5e65e 100644
--- a/lib/backends/webgl/ops/concat_packed.ts
+++ b/lib/backends/webgl/ops/concat_packed.ts
@@ -45,7 +45,8 @@ export class WebGLPackedConcat extends Concat implements WebGLOperator {
     const unpackChannel = unpackFromChannel();
 
     const shapes = inputs.map(i => i.dims);
-    const channels = ['x', 'y', 'z', 'w', 'u', 'v'].slice(0, rank);
+    const allGlChannels = ['x', 'y', 'z', 'w', 'u', 'v'];
+    const channels = allGlChannels.slice(0, rank);
     const offsets: number[] = new Array(shapes.length - 1);
     const samplers = inputs.map((v, i) => `X${i}`);
 
@@ -88,6 +89,10 @@ export class WebGLPackedConcat extends Concat implements WebGLOperator {
 
         void main() {
           ${dtype} coords = getOutputCoords();
+          int lastDim = coords.${allGlChannels[rank - 1]};
+          coords.${allGlChannels[rank - 1]} = coords.${allGlChannels[rank - 2]};
+          coords.${allGlChannels[rank - 2]} = lastDim;
+
           vec4 result = vec4(getValue(${coords}), 0., 0., 0.);
 
           ${coords[rank - 1]} = ${coords[rank - 1]} + 1;
@@ -110,8 +115,9 @@ export class WebGLPackedConcat extends Concat implements WebGLOperator {
       `;
 
     return {
-      inputLayouts: inputs.map(t => handler.getOrCreateTextureLayout(t)),
-      outputLayout: handler.createTextureLayoutFromShape(outputShape),
+      inputLayouts: inputs.map(t => handler.getOrCreateTextureLayout(t, 4, true, t.dims, true)),
+      outputLayout:
+          handler.createTextureLayoutFromShape(outputShape, 4, outputShape, {isPacked: true, reverseWH: true}),
       samplers,
       shaderSource,
       hasMain: true,
@@ -120,7 +126,7 @@ export class WebGLPackedConcat extends Concat implements WebGLOperator {
     };
   }
   createRunData(handler: WebGLInferenceHandler, programInfo: ProgramInfo, inputs: Tensor[]): RunData {
-    const inputTDs = inputs.map((t, i) => handler.getOrCreateTextureData(t, programInfo.inputLayouts[i]));
+    const inputTDs = inputs.map((t, i) => handler.getOrCreateTextureData(t, programInfo.inputLayouts[i], true));
     return {
       inputTextureDatas: inputTDs,
       outputTextureData: handler.createTextureDataFromLayout(programInfo.outputLayout, inputTDs[0].tensor.type),
diff --git a/test/unittests/backends/webgl/test_concat_packed.ts b/test/unittests/backends/webgl/test_concat_packed.ts
index f545710a..a2776f6d 100644
--- a/test/unittests/backends/webgl/test_concat_packed.ts
+++ b/test/unittests/backends/webgl/test_concat_packed.ts
@@ -39,6 +39,7 @@ describe('#UnitTest# - packed concat - Tensor concat', () => {
     describe(`Test concat ${JSON.stringify(testData)}`, () => {});
     it(`Test packed concat kernel `, () => {
       const webglInferenceHandler = inferenceHandler as WebGLInferenceHandler;
+      // webglInferenceHandler.session.pack = false;
 
       // TODO support WebGl 1.0
       if (webglInferenceHandler.session.textureManager.glContext.version === 1) {
@@ -55,7 +56,6 @@ describe('#UnitTest# - packed concat - Tensor concat', () => {
       const elementCount = testData.elementCount;
       const inputTensorShape = testData.inputShape;
       const inputTextureShape = testData.inputTextureShape;
-      const outputTensorShape = testData.outputShape;
 
       // create input data and tensor. The input data will be used to verify if the output tensor contains the
       // same value but possibly different order depending on our packing algorithm.
@@ -65,6 +65,7 @@ describe('#UnitTest# - packed concat - Tensor concat', () => {
 
       // manually creat packed texture from inputTensor, and insert in cache
       const gl = webglInferenceHandler.session.textureManager.glContext.gl;
+
       webglInferenceHandler.session.textureManager.glContext.checkError();
       const webglTextureA = createTextureFromArray(
           webglInferenceHandler.session.textureManager.glContext, testData.rawInput ? testData.rawInput : inputData,
@@ -82,7 +83,7 @@ describe('#UnitTest# - packed concat - Tensor concat', () => {
         isPacked: true,
         shape: packedShape,
         strides: ShapeUtil.computeStrides(packedShape),
-        unpackedShape: outputTensorShape,
+        unpackedShape: inputTensorShape,
         tensor: inputTensorA,
         texture: webglTextureA!
       };
@@ -93,13 +94,13 @@ describe('#UnitTest# - packed concat - Tensor concat', () => {
         isPacked: true,
         shape: packedShape,
         strides: ShapeUtil.computeStrides(packedShape),
-        unpackedShape: outputTensorShape,
+        unpackedShape: inputTensorShape,
         tensor: inputTensorB,
         texture: webglTextureB!
       };
 
-      webglInferenceHandler.setTextureData(inputTensorA.dataId, textureDataA);
-      webglInferenceHandler.setTextureData(inputTensorB.dataId, textureDataB);
+      webglInferenceHandler.setTextureData(inputTensorA.dataId, textureDataA, true);
+      webglInferenceHandler.setTextureData(inputTensorB.dataId, textureDataB, true);
 
       // compile shader code
       const programInfo =
@@ -117,7 +118,6 @@ describe('#UnitTest# - packed concat - Tensor concat', () => {
       // verify result.
       const expectedOutput = testData.expectedOutput;
       expect(result).to.not.equal(null);
-
       expect(result).to.have.lengthOf(elementCount * 2);
 
       expect(result).to.deep.equal(expectedOutput);
@@ -167,24 +167,7 @@ function getTestData(): TestData[] {
       outputShape: [4, 4],
       inputTextureShape: [2, 1],
       outputTextureShape: [2, 2],
-      expectedOutput: new Float32Array([
-        1,
-        2,
-        5,
-        6,
-        3,
-        4,
-        7,
-        8,
-        1,
-        2,
-        5,
-        6,
-        3,
-        4,
-        7,
-        8,
-      ]),
+      expectedOutput: new Float32Array([1, 2, 5, 6, 3, 4, 7, 8, 1, 2, 5, 6, 3, 4, 7, 8]),
     },
     {
       elementCount: 8,
@@ -192,7 +175,7 @@ function getTestData(): TestData[] {
       inputShape: [2, 4],
       outputShape: [2, 8],
       inputTextureShape: [2, 1],
-      outputTextureShape: [2, 4],
+      outputTextureShape: [4, 2],
       expectedOutput: new Float32Array([
         1,
         2,
@@ -291,8 +274,8 @@ function getTestData(): TestData[] {
       outputTextureShape: [8, 4],
       expectedOutput: new Float32Array([
         1,  2,  5,  6,  3,  4,  7,  8,  9,  10, 13, 14, 11, 12, 15, 16, 1,  2,  5,  6,  3,  4,
-        7,  8,  9,  10, 13, 14, 11, 12, 15, 16, 25, 26, 29, 30, 27, 28, 31, 32, 25, 26, 29, 30,
-        27, 28, 31, 32, 25, 26, 29, 30, 27, 28, 31, 32, 25, 26, 29, 30, 27, 28, 31, 32
+        7,  8,  9,  10, 13, 14, 11, 12, 15, 16, 17, 18, 21, 22, 19, 20, 23, 24, 25, 26, 29, 30,
+        27, 28, 31, 32, 17, 18, 21, 22, 19, 20, 23, 24, 25, 26, 29, 30, 27, 28, 31, 32
       ])
     },
 
@@ -304,9 +287,9 @@ function getTestData(): TestData[] {
       inputTextureShape: [2, 4],
       outputTextureShape: [8, 4],
       expectedOutput: new Float32Array([
-        1,  2,  5,  6,  3,  4,  7,  8,  1,  2,  5,  6,  3,  4,  7,  8,  17, 18, 21, 22, 19, 20,
-        23, 24, 17, 18, 21, 22, 19, 20, 23, 24, 25, 26, 29, 30, 27, 28, 31, 32, 25, 26, 29, 30,
-        27, 28, 31, 32, 25, 26, 29, 30, 27, 28, 31, 32, 25, 26, 29, 30, 27, 28, 31, 32
+        1,  2,  5,  6,  3,  4,  7,  8,  1,  2,  5,  6,  3,  4,  7,  8,  9,  10, 13, 14, 11, 12,
+        15, 16, 9,  10, 13, 14, 11, 12, 15, 16, 17, 18, 21, 22, 19, 20, 23, 24, 17, 18, 21, 22,
+        19, 20, 23, 24, 25, 26, 29, 30, 27, 28, 31, 32, 25, 26, 29, 30, 27, 28, 31, 32
       ])
     },
     {
@@ -317,9 +300,9 @@ function getTestData(): TestData[] {
       inputTextureShape: [2, 4],
       outputTextureShape: [8, 4],
       expectedOutput: new Float32Array([
-        1,  2,  5,  6,  1,  2,  5,  6,  3,  4,  7,  8,  3,  4,  7,  8,  17, 18, 21, 22, 17, 18,
-        21, 22, 19, 20, 23, 24, 19, 20, 23, 24, 25, 26, 29, 30, 25, 26, 29, 30, 27, 28, 31, 32,
-        27, 28, 31, 32, 25, 26, 29, 30, 25, 26, 29, 30, 27, 28, 31, 32, 27, 28, 31, 32
+        1,  2,  5,  6,  1,  2,  5,  6,  3,  4,  7,  8,  3,  4,  7,  8,  9,  10, 13, 14, 9,  10,
+        13, 14, 11, 12, 15, 16, 11, 12, 15, 16, 17, 18, 21, 22, 17, 18, 21, 22, 19, 20, 23, 24,
+        19, 20, 23, 24, 25, 26, 29, 30, 25, 26, 29, 30, 27, 28, 31, 32, 27, 28, 31, 32
       ])
     },
   ];