diff --git a/server/initializers/constants.ts b/server/initializers/constants.ts
index c06eb6fb0..0b4b41273 100644
--- a/server/initializers/constants.ts
+++ b/server/initializers/constants.ts
@@ -274,8 +274,6 @@ const CONSTRAINTS_FIELDS = {
     DURATION: { min: 0 }, // Number
     TAGS: { min: 0, max: 5 }, // Number of total tags
     TAG: { min: 2, max: 30 }, // Length
-    THUMBNAIL: { min: 2, max: 30 },
-    THUMBNAIL_DATA: { min: 0, max: 20000 }, // Bytes
     VIEWS: { min: 0 },
     LIKES: { min: 0 },
     DISLIKES: { min: 0 },
@@ -750,6 +748,7 @@ if (isTestInstance() === true) {
   ACTIVITY_PUB.VIDEO_PLAYLIST_REFRESH_INTERVAL = 10 * 1000 // 10 seconds
 
   CONSTRAINTS_FIELDS.ACTORS.AVATAR.FILE_SIZE.max = 100 * 1024 // 100KB
+  CONSTRAINTS_FIELDS.VIDEOS.IMAGE.FILE_SIZE.max = 400 * 1024 // 400KB
 
   SCHEDULER_INTERVALS_MS.actorFollowScores = 1000
   SCHEDULER_INTERVALS_MS.removeOldJobs = 10000
diff --git a/server/tests/api/check-params/live.ts b/server/tests/api/check-params/live.ts
index a5493572b..c171b1f81 100644
--- a/server/tests/api/check-params/live.ts
+++ b/server/tests/api/check-params/live.ts
@@ -180,7 +180,7 @@ describe('Test video lives API validator', function () {
     it('Should fail with an incorrect thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'avatar.png')
+        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'video_short.mp4')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
@@ -189,7 +189,7 @@ describe('Test video lives API validator', function () {
     it('Should fail with a big thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'avatar-big.png')
+        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'preview-big.png')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
@@ -198,7 +198,7 @@ describe('Test video lives API validator', function () {
     it('Should fail with an incorrect preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(__dirname, '..', '..', 'fixtures', 'avatar.png')
+        previewfile: join(__dirname, '..', '..', 'fixtures', 'video_short.mp4')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
@@ -207,7 +207,7 @@ describe('Test video lives API validator', function () {
     it('Should fail with a big preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(__dirname, '..', '..', 'fixtures', 'avatar-big.png')
+        previewfile: join(__dirname, '..', '..', 'fixtures', 'preview-big.png')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
diff --git a/server/tests/api/check-params/video-imports.ts b/server/tests/api/check-params/video-imports.ts
index 49ff96117..6de6b40c8 100644
--- a/server/tests/api/check-params/video-imports.ts
+++ b/server/tests/api/check-params/video-imports.ts
@@ -201,7 +201,7 @@ describe('Test video imports API validator', function () {
     it('Should fail with an incorrect thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'avatar.png')
+        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'video_short.mp4')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
@@ -210,7 +210,7 @@ describe('Test video imports API validator', function () {
     it('Should fail with a big thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'avatar-big.png')
+        thumbnailfile: join(__dirname, '..', '..', 'fixtures', 'preview-big.png')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
@@ -219,7 +219,7 @@ describe('Test video imports API validator', function () {
     it('Should fail with an incorrect preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(__dirname, '..', '..', 'fixtures', 'avatar.png')
+        previewfile: join(__dirname, '..', '..', 'fixtures', 'video_short.mp4')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
@@ -228,7 +228,7 @@ describe('Test video imports API validator', function () {
     it('Should fail with a big preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(__dirname, '..', '..', 'fixtures', 'avatar-big.png')
+        previewfile: join(__dirname, '..', '..', 'fixtures', 'preview-big.png')
       }
 
       await makeUploadRequest({ url: server.url, path, token: server.accessToken, fields, attaches })
diff --git a/server/tests/api/check-params/video-playlists.ts b/server/tests/api/check-params/video-playlists.ts
index 418af05d1..bbea88354 100644
--- a/server/tests/api/check-params/video-playlists.ts
+++ b/server/tests/api/check-params/video-playlists.ts
@@ -251,7 +251,14 @@ describe('Test video playlists API validator', function () {
     })
 
     it('Should fail with an incorrect thumbnail file', async function () {
-      const params = getBase({ thumbnailfile: 'avatar.png' })
+      const params = getBase({ thumbnailfile: 'video_short.mp4' })
+
+      await createVideoPlaylist(params)
+      await updateVideoPlaylist(getUpdate(params, playlistUUID))
+    })
+
+    it('Should fail with a thumbnail file too big', async function () {
+      const params = getBase({ thumbnailfile: 'preview-big.png' })
 
       await createVideoPlaylist(params)
       await updateVideoPlaylist(getUpdate(params, playlistUUID))
diff --git a/server/tests/api/check-params/videos.ts b/server/tests/api/check-params/videos.ts
index 5faba82c4..188d1835c 100644
--- a/server/tests/api/check-params/videos.ts
+++ b/server/tests/api/check-params/videos.ts
@@ -373,7 +373,7 @@ describe('Test videos API validator', function () {
     it('Should fail with an incorrect thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'avatar.png'),
+        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4'),
         videofile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4')
       }
 
@@ -383,7 +383,7 @@ describe('Test videos API validator', function () {
     it('Should fail with a big thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'avatar-big.png'),
+        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'preview-big.png'),
         videofile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4')
       }
 
@@ -393,7 +393,7 @@ describe('Test videos API validator', function () {
     it('Should fail with an incorrect preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(root(), 'server', 'tests', 'fixtures', 'avatar.png'),
+        previewfile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4'),
         videofile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4')
       }
 
@@ -403,7 +403,7 @@ describe('Test videos API validator', function () {
     it('Should fail with a big preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(root(), 'server', 'tests', 'fixtures', 'avatar-big.png'),
+        previewfile: join(root(), 'server', 'tests', 'fixtures', 'preview-big.png'),
         videofile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4')
       }
 
@@ -581,7 +581,7 @@ describe('Test videos API validator', function () {
     it('Should fail with an incorrect thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'avatar.png')
+        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4')
       }
 
       await makeUploadRequest({
@@ -597,7 +597,7 @@ describe('Test videos API validator', function () {
     it('Should fail with a big thumbnail file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'avatar-big.png')
+        thumbnailfile: join(root(), 'server', 'tests', 'fixtures', 'preview-big.png')
       }
 
       await makeUploadRequest({
@@ -613,7 +613,7 @@ describe('Test videos API validator', function () {
     it('Should fail with an incorrect preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(root(), 'server', 'tests', 'fixtures', 'avatar.png')
+        previewfile: join(root(), 'server', 'tests', 'fixtures', 'video_short.mp4')
       }
 
       await makeUploadRequest({
@@ -629,7 +629,7 @@ describe('Test videos API validator', function () {
     it('Should fail with a big preview file', async function () {
       const fields = baseCorrectParams
       const attaches = {
-        previewfile: join(root(), 'server', 'tests', 'fixtures', 'avatar-big.png')
+        previewfile: join(root(), 'server', 'tests', 'fixtures', 'preview-big.png')
       }
 
       await makeUploadRequest({
diff --git a/server/tests/fixtures/preview-big.png b/server/tests/fixtures/preview-big.png
new file mode 100644
index 000000000..612e297f1
Binary files /dev/null and b/server/tests/fixtures/preview-big.png differ