diff --git a/frontend/src/Photos/PhotoCard.tsx b/frontend/src/Photos/PhotoCard.tsx
index caa725e..b1faa2e 100644
--- a/frontend/src/Photos/PhotoCard.tsx
+++ b/frontend/src/Photos/PhotoCard.tsx
@@ -1,11 +1,18 @@
-import { Card, ContextMenuTarget, Menu, MenuItem } from "@blueprintjs/core";
+import {
+    Card,
+    ContextMenuTarget,
+    Menu,
+    MenuItem,
+    Spinner,
+} from "@blueprintjs/core";
 import * as React from "react";
 import { IPhotoReqJSON } from "~../../src/entity/Photo";
-import { getPhotoImgPath } from "~redux/api/photos";
+import { getPhotoImgPath, getPhotoThumbPath } from "~redux/api/photos";
 import { showDeletionToast } from "~AppToaster";
 import { Dispatch } from "redux";
 import { photoDeleteCancel, photoDeleteStart } from "~redux/photos/actions";
 import { connect } from "react-redux";
+import { LoadingStub } from "~LoadingStub";
 
 export interface IPhotoCardComponentProps {
     photo: IPhotoReqJSON;
@@ -35,6 +42,7 @@ export class PhotoCardComponent extends React.PureComponent<
     }
     */
     public render(): JSX.Element {
+        const isUploaded = this.props.photo.uploaded;
         return (
             <Card
                 className="photoCard"
@@ -45,7 +53,11 @@ export class PhotoCardComponent extends React.PureComponent<
                 }
             */
             >
-                <img src={getPhotoImgPath(this.props.photo)}></img>
+                {isUploaded ? (
+                    <img src={getPhotoThumbPath(this.props.photo, 512)}></img>
+                ) : (
+                    <Spinner />
+                )}
             </Card>
         );
     }
diff --git a/frontend/src/redux/api/photos.ts b/frontend/src/redux/api/photos.ts
index 2979dc1..bcf408e 100644
--- a/frontend/src/redux/api/photos.ts
+++ b/frontend/src/redux/api/photos.ts
@@ -12,6 +12,12 @@ export function getPhotoImgPath(photo: IPhotoReqJSON): string {
     return `${apiRoot}/photos/showByID/${photo.id}/${photo.accessToken}`;
 }
 
+export function getPhotoThumbPath(photo: IPhotoReqJSON, size: number): string {
+    return `${apiRoot}/photos/showByID/${photo.id}/${
+        photo.accessToken
+    }?size=${size.toString()}`;
+}
+
 export async function fetchPhotosList(): Promise<IPhotosListRespBody> {
     return fetchJSONAuth("/photos/list", "GET");
 }
diff --git a/src/entity/Photo.ts b/src/entity/Photo.ts
index 1776359..92b5d35 100644
--- a/src/entity/Photo.ts
+++ b/src/entity/Photo.ts
@@ -21,12 +21,15 @@ import {
     isAlphanumeric,
     IsAlphanumeric,
     IsHash,
+    IsIn,
     IsMimeType,
+    isNumber,
     Length,
     Matches,
     validateOrReject,
 } from "class-validator";
 import { config } from "~config";
+import { resizeTo } from "~util";
 
 export interface IPhotoJSON {
     id: number;
@@ -37,12 +40,15 @@ export interface IPhotoJSON {
     createdAt: number;
     editedAt: number;
     shotAt: number;
+    uploaded: boolean;
 }
 
 export interface IPhotoReqJSON extends IPhotoJSON {
     accessToken: string;
 }
 
+export const ThumbSizes = ["512", "1024", "2048"];
+
 @Entity()
 @Index(["hash", "size", "user"], { unique: true })
 export class Photo extends BaseEntity {
@@ -63,6 +69,9 @@ export class Photo extends BaseEntity {
     @IsMimeType()
     public format: string;
 
+    @Column({ type: "set", enum: ThumbSizes, default: [] })
+    public generatedThumbs: string[];
+
     @Column({ type: "varchar", length: 500 })
     public accessToken: string;
 
@@ -87,10 +96,20 @@ export class Photo extends BaseEntity {
         }`;
     }
 
+    private getThumbFileName(size: number): string {
+        return `${this.user.id.toString()}-${this.hash}-${this.size}-${size}.${
+            mime.extension(this.format) as string
+        }`;
+    }
+
     public getPath(): string {
         return path.join(this.user.getDataPath(), this.getFileName());
     }
 
+    private getThumbPath(size: number): string {
+        return path.join(this.user.getDataPath(), this.getThumbFileName(size));
+    }
+
     @BeforeInsert()
     async beforeInsertValidate(): Promise<void> {
         return validateOrReject(this);
@@ -105,6 +124,12 @@ export class Photo extends BaseEntity {
     async cleanupFiles(): Promise<void> {
         try {
             await fs.unlink(this.getPath());
+            await Promise.all(
+                this.generatedThumbs.map(
+                    async (size) =>
+                        await fs.unlink(this.getThumbPath(parseInt(size))),
+                ),
+            );
         } catch (e) {
             if (e.code !== "ENOENT") {
                 throw e;
@@ -121,6 +146,26 @@ export class Photo extends BaseEntity {
         }
     }
 
+    private async generateThumbnail(size: number): Promise<void> {
+        if (!(await this.isUploaded())) {
+            return;
+        }
+        await resizeTo(this.getPath(), this.getThumbPath(size), size);
+        this.generatedThumbs.push(size.toString());
+        await this.save();
+    }
+
+    public async getReadyThumbnailPath(size: number): Promise<string> {
+        if (!ThumbSizes.includes(size.toString())) {
+            throw new Error("Wrong thumbnail size");
+        }
+        const path = this.getThumbPath(size);
+        if (!this.generatedThumbs.includes(size.toString())) {
+            await this.generateThumbnail(size);
+        }
+        return path;
+    }
+
     constructor(user: User, hash: string, size: string, format: string) {
         super();
         this.createdAt = new Date();
@@ -132,6 +177,7 @@ export class Photo extends BaseEntity {
         this.format = format;
         this.size = size;
         this.user = user;
+        this.generatedThumbs = [];
     }
 
     public async getJWTToken(): Promise<string> {
@@ -141,7 +187,7 @@ export class Photo extends BaseEntity {
         if (tokenExpiryOld - now - 60 * 10 * 1000 > 0) {
             return this.accessToken;
         } else {
-            const token = jwt.sign(this.toJSON(), config.jwtSecret, {
+            const token = jwt.sign(await this.toJSON(), config.jwtSecret, {
                 expiresIn: "1h",
                 algorithm: "HS256",
             });
@@ -152,7 +198,10 @@ export class Photo extends BaseEntity {
         }
     }
 
-    public toJSON(): IPhotoJSON {
+    public async toJSON(): Promise<IPhotoJSON> {
+        if (!isNumber(this.user.id)) {
+            throw new Error("User not loaded");
+        }
         return {
             id: this.id,
             user: this.user.id,
@@ -162,11 +211,12 @@ export class Photo extends BaseEntity {
             createdAt: this.createdAt.getTime(),
             editedAt: this.editedAt.getTime(),
             shotAt: this.shotAt.getTime(),
+            uploaded: await this.isUploaded(),
         };
     }
 
     public async toReqJSON(): Promise<IPhotoReqJSON> {
         const token = await this.getJWTToken();
-        return { ...this.toJSON(), accessToken: token };
+        return { ...(await this.toJSON()), accessToken: token };
     }
 }
diff --git a/src/routes/photos.ts b/src/routes/photos.ts
index d7b1326..2338af3 100644
--- a/src/routes/photos.ts
+++ b/src/routes/photos.ts
@@ -30,7 +30,7 @@ photosRouter.post("/photos/new", async (ctx) => {
         return;
     }
 
-    const photo = new Photo(user.id, hash, size, format);
+    const photo = new Photo(user, hash, size, format);
 
     try {
         await photo.save();
@@ -241,6 +241,12 @@ photosRouter.get("/photos/showByID/:id/:token", async (ctx) => {
         return;
     }
 
+    if (ctx.request.query["size"]) {
+        const size = parseInt(ctx.request.query["size"]);
+        await send(ctx, await photo.getReadyThumbnailPath(size));
+        return;
+    }
+
     await send(ctx, photo.getPath());
 });
 
@@ -266,6 +272,12 @@ photosRouter.get("/photos/showByID/:id", async (ctx) => {
         return;
     }
 
+    if (ctx.request.query["size"]) {
+        const size = parseInt(ctx.request.query["size"]);
+        await send(ctx, await photo.getReadyThumbnailPath(size));
+        return;
+    }
+
     await send(ctx, photo.getPath());
 });
 
diff --git a/src/tests/integration/photos.test.ts b/src/tests/integration/photos.test.ts
index 03e43a9..19eccc6 100644
--- a/src/tests/integration/photos.test.ts
+++ b/src/tests/integration/photos.test.ts
@@ -82,6 +82,18 @@ describe("photos", function () {
         );
     });
 
+    it("should show a thumbnail", async function () {
+        const response = await request(callback)
+            .get(`/photos/showByID/${seed.dogPhoto.id}?size=512`)
+            .set({
+                Authorization: `Bearer ${seed.user2.toJWT()}`,
+            })
+            .expect(200);
+        expect(parseInt(response.header["content-length"])).to.be.lessThan(
+            dogFileSize,
+        );
+    });
+
     it("should show a photo using access token", async function () {
         const listResp = await request(callback)
             .get(`/photos/list`)
@@ -524,6 +536,9 @@ describe("photos", function () {
 
     it("should delete a photo", async function () {
         const photoPath = seed.dogPhoto.getPath();
+        const photoSmallThumbPath = await seed.dogPhoto.getReadyThumbnailPath(
+            512,
+        );
         const response = await request(callback)
             .delete(`/photos/byID/${seed.dogPhoto.id}`)
             .set({
@@ -537,6 +552,7 @@ describe("photos", function () {
 
         try {
             await fs.access(photoPath, fsConstants.F_OK);
+            await fs.access(photoSmallThumbPath, fsConstants.F_OK);
             assert(false);
         } catch (e) {
             assert(true);
diff --git a/src/util.ts b/src/util.ts
index c71ff87..a92cec6 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -18,6 +18,14 @@ export async function getSize(file: string): Promise<string> {
     return `${metadata.width}x${metadata.height}`;
 }
 
+export async function resizeTo(
+    inPath: string,
+    outPath: string,
+    size: number,
+): Promise<void> {
+    await sharp(inPath).resize(size, size).withMetadata().toFile(outPath);
+}
+
 // eslint-disable-next-line @typescript-eslint/no-misused-promises
 export const getHashSync: (file: string) => string = deasync(getHash);
 // eslint-disable-next-line @typescript-eslint/no-misused-promises