diff --git a/app/emoji.go b/app/emoji.go
index 48e7773b5a..9982428711 100644
--- a/app/emoji.go
+++ b/app/emoji.go
@@ -14,7 +14,6 @@ import (
 	"image/draw"
 	"image/gif"
 	_ "image/jpeg"
-	"image/png"
 	"io"
 	"mime/multipart"
 	"net/http"
@@ -31,7 +30,7 @@ import (
 )
 
 const (
-	MaxEmojiFileSize       = 1 << 20 // 1 MB
+	MaxEmojiFileSize       = 1 << 19 // 512 KiB
 	MaxEmojiWidth          = 128
 	MaxEmojiHeight         = 128
 	MaxEmojiOriginalWidth  = 1028
@@ -155,8 +154,8 @@ func (a *App) UploadEmojiImage(c request.CTX, id string, imageData *multipart.Fi
 				return model.NewAppError("uploadEmojiImage", "api.emoji.upload.large_image.decode_error", nil, "", http.StatusBadRequest).Wrap(err)
 			}
 
-			resized_image := resizeEmoji(img, config.Width, config.Height)
-			if err := png.Encode(newbuf, resized_image); err != nil {
+			resizedImg := resizeEmoji(img, config.Width, config.Height)
+			if err := a.ch.imgEncoder.EncodePNG(newbuf, resizedImg); err != nil {
 				return model.NewAppError("uploadEmojiImage", "api.emoji.upload.large_image.encode_error", nil, "", http.StatusBadRequest).Wrap(err)
 			}
 			buf = newbuf
diff --git a/app/imaging/encode.go b/app/imaging/encode.go
index 1afb3159d9..d10f73c91a 100644
--- a/app/imaging/encode.go
+++ b/app/imaging/encode.go
@@ -45,7 +45,9 @@ func NewEncoder(opts EncoderOptions) (*Encoder, error) {
 		e.sem = make(chan struct{}, opts.ConcurrencyLevel)
 	}
 	e.opts = opts
-	e.pngEncoder = &png.Encoder{}
+	e.pngEncoder = &png.Encoder{
+		CompressionLevel: png.BestCompression,
+	}
 	return &e, nil
 }
 
diff --git a/app/user_test.go b/app/user_test.go
index 086e71e25f..b4a57dd32a 100644
--- a/app/user_test.go
+++ b/app/user_test.go
@@ -121,7 +121,7 @@ func TestAdjustProfileImage(t *testing.T) {
 	assert.True(t, adjusted.Len() > 0)
 	assert.NotEqual(t, testjpg, adjusted)
 
-	// default image should require adjustment
+	// default image should not require adjustment
 	user := th.BasicUser
 	image, err := th.App.GetDefaultProfileImage(user)
 	require.Nil(t, err)
diff --git a/app/users/profile_picture.go b/app/users/profile_picture.go
index 1858140e52..4a9c73f36f 100644
--- a/app/users/profile_picture.go
+++ b/app/users/profile_picture.go
@@ -160,7 +160,10 @@ func createProfileImage(username string, userID string, initialFont string) ([]b
 
 	buf := new(bytes.Buffer)
 
-	if imgErr := png.Encode(buf, dstImg); imgErr != nil {
+	enc := png.Encoder{
+		CompressionLevel: png.BestCompression,
+	}
+	if imgErr := enc.Encode(buf, dstImg); imgErr != nil {
 		return nil, ImageEncodingError
 	}
 
diff --git a/i18n/en.json b/i18n/en.json
index 0fac9e2df3..c9d23f4a46 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -1719,7 +1719,7 @@
   },
   {
     "id": "api.emoji.create.too_large.app_error",
-    "translation": "Unable to create emoji. Image must be less than 1 MB in size."
+    "translation": "Unable to create emoji. Image must be less than 512 KiB in size."
   },
   {
     "id": "api.emoji.disabled.app_error",
diff --git a/tests/10000x1_expected_preview.png b/tests/10000x1_expected_preview.png
index bf2ca9cc21..6c48a52421 100644
Binary files a/tests/10000x1_expected_preview.png and b/tests/10000x1_expected_preview.png differ
diff --git a/tests/10000x1_expected_thumb.png b/tests/10000x1_expected_thumb.png
index a354c41047..93a8cb3667 100644
Binary files a/tests/10000x1_expected_thumb.png and b/tests/10000x1_expected_thumb.png differ
diff --git a/tests/1x10000_expected_preview.png b/tests/1x10000_expected_preview.png
index b4317244e9..ba938e6aef 100644
Binary files a/tests/1x10000_expected_preview.png and b/tests/1x10000_expected_preview.png differ
diff --git a/tests/1x10000_expected_thumb.png b/tests/1x10000_expected_thumb.png
index 71dd5eba8f..4078828348 100644
Binary files a/tests/1x10000_expected_thumb.png and b/tests/1x10000_expected_thumb.png differ
diff --git a/tests/fill_test_16bit_rgb_out.png b/tests/fill_test_16bit_rgb_out.png
index bb9741d53f..72f7b9ca99 100644
Binary files a/tests/fill_test_16bit_rgb_out.png and b/tests/fill_test_16bit_rgb_out.png differ
diff --git a/tests/fill_test_16bit_rgba_out.png b/tests/fill_test_16bit_rgba_out.png
index 491bee1ce5..7e521ccbe6 100644
Binary files a/tests/fill_test_16bit_rgba_out.png and b/tests/fill_test_16bit_rgba_out.png differ
diff --git a/tests/fill_test_8bit_palette_out.png b/tests/fill_test_8bit_palette_out.png
index d865b78def..5feebf44cd 100644
Binary files a/tests/fill_test_8bit_palette_out.png and b/tests/fill_test_8bit_palette_out.png differ
diff --git a/tests/fill_test_8bit_rgb_out.png b/tests/fill_test_8bit_rgb_out.png
index 499026d665..3214f84c0f 100644
Binary files a/tests/fill_test_8bit_rgb_out.png and b/tests/fill_test_8bit_rgb_out.png differ
diff --git a/tests/fill_test_8bit_rgba_out.png b/tests/fill_test_8bit_rgba_out.png
index bd5c157f2a..3167887d9d 100644
Binary files a/tests/fill_test_8bit_rgba_out.png and b/tests/fill_test_8bit_rgba_out.png differ