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Social Media Image Resizer Online

Browser-side — no upload
Last verified May 2026 — runs in your browser

Social Media Resizer — One-Click Platform Presets

Resize any photo to the exact pixel dimensions each social platform currently publishes (verified 2026): Instagram feed square 1080×1080, portrait 1080×1350 (Instagram's default since 2026, per the help.instagram.com sizes guide), landscape 1080×566, story / reel 1080×1920 (9:16); X (formerly Twitter) header 1500×500 (3:1), profile 400×400, in-feed post 1200×675; Facebook OG / share image 1200×630; LinkedIn personal banner 1584×396 (4:1), single-image feed post 1200×627; YouTube video thumbnail 1280×720 (16:9, JPG / GIF / PNG, ≤ 2 MB on mobile uploads or 50 MB on desktop per support.google.com/youtube/answer/72431). The crop+resize pipeline runs locally via the WHATWG Canvas 2D Context drawImage() API: the source is centre-cropped to the platform's aspect ratio first, then drawn to a target canvas at the platform's exact pixel dimensions with imageSmoothingQuality = 'high' (Lanczos-class kernel per Duchon 1979). Output is encoded via HTMLCanvasElement.toBlob() in JPG, PNG, or WebP and rendered in sRGB at 8-bit precision per IEC 61966-2-1:1999 — which is what every social platform expects (uploads in Display P3 or BT.2020 get tone-mapped to sRGB by the platform's own pipeline anyway). Files never leave the device.

Related: Bulk Resize Resize Image Aspect Ratio Crop Image Grid Splitter Image Upscaler Crop Image

How to resize for social media

  1. Drop your image onto the tool or click to browse. Source decoding happens locally via the browser's built-in JPG / PNG / WebP decoder.
  2. Pick a platform preset — Instagram feed (square / portrait / landscape), Instagram story / reel (9:16), X header (3:1), Facebook share (1.91:1), LinkedIn banner (4:1), LinkedIn post (1.91:1), YouTube thumbnail (16:9).
  3. The tool centre-crops the source to the platform's aspect ratio first, then runs drawImage() with imageSmoothingQuality = 'high' (Lanczos-class kernel) to scale to the platform's exact pixel dimensions.
  4. Review the live preview. If your subject is off-centre, pre-crop the source with the aspect-ratio-crop tool first so the subject lands in the middle of the platform's crop window.
  5. Download the resized image and upload straight to the platform without re-exporting from a design tool.

Common use cases

  • Adapting a single product photo to every social channel's hero image dimensions in one session — IG feed + IG story + X header + LinkedIn post + Facebook share + YouTube thumbnail from one source.
  • Resizing a personal portrait into X profile (400×400), LinkedIn profile (recommended 400×400), and Facebook profile sizes at once for a coordinated brand refresh.
  • Preparing YouTube thumbnails at exactly 1280×720 within the upload size limit (2 MB mobile / 50 MB desktop) without re-exporting from a desktop editor — the tool ships the format constraints YouTube enforces.
  • Producing LinkedIn banner variants (1584×396) for different roles or campaigns by reusing the same source photo.
  • Generating Instagram portrait posts at 1080×1350 (the default since 2026) from a 16:9 camera shot without losing key subject detail to Instagram's centre-crop.

Frequently asked questions

Are the platform specs up to date?

The presets ship the dimensions each platform currently publishes (verified 2026 against help.instagram.com, help.x.com, linkedin.com/help, support.google.com/youtube). Social platforms occasionally adjust defaults — Instagram switched its default feed format from square 1:1 to portrait 4:5 (1080×1350) in 2026, for example. The tool aims to track those updates; check the platform's own help centre if you need the absolute latest spec.

Will my subject get cropped?

The tool uses a centre crop to fit the source aspect ratio to the platform's required ratio. If your subject sits off-centre — e.g. a face in the upper third of a landscape source going into a 1080×1920 IG story — pre-crop the source with the aspect-ratio-crop tool first so the subject lands in the middle of the target window. The live preview shows the crop frame before export, so off-centre subjects are visible upfront.

Can I customise the output size?

For non-preset dimensions use the resize-image tool with explicit width × height, or the bulk-resize tool with a custom target width. The aspect-ratio-crop tool handles non-standard ratios. The social-media-resizer is intentionally preset-only because the value is in the verified platform-spec dimensions, not free-form input.

Why does my upload still look soft after using the tool?

Two common causes: (1) the source was already low-resolution and upscaling cannot invent detail (Lanczos-class kernels redistribute existing samples; they don't generate new edges) — start from a higher-resolution source if possible. (2) The platform re-encodes your upload regardless of how well-prepared it was; Instagram in particular runs aggressive JPG quantisation at upload time. The tool's contribution is matching the platform's exact pixel dimensions and aspect ratio so the platform's resize pass is a no-op rather than a destructive scale-and-crop.

Is my image uploaded?

No. The crop and resize run entirely in the browser via the WHATWG Canvas 2D Context. Files never leave the device — DevTools Network tab shows zero upload requests during the operation. The downloaded result is exposed via URL.createObjectURL from the in-memory Blob.

Why platform-spec matching matters — and what changes when you skip it

Every social platform runs an upload-side image pipeline that resizes, re-encodes, and crops to its own spec; getting close to the target is not the same as hitting the target. (1) Instagram's feed crop window is 4:5 (portrait) by default since 2026 — uploading a 1:1 square works but loses ~25% of vertical screen real estate; uploading a wider 16:9 photo gets centre-cropped to 4:5, often hiding faces near the top or bottom. The 1080×1350 preset matches Instagram's preferred portrait container exactly. (2) X (Twitter) header banners use a 3:1 ratio at 1500×500; the profile picture overlays the bottom-left ~200×200 area, so the bottom-left of your header is partially obscured. The preset crops centre but you can see the safe zone in the preview. (3) LinkedIn personal banners are 4:1 at 1584×396, and LinkedIn's mobile crop trims the left and right edges aggressively — keep important content within a centred ~1200×300 safe zone. (4) YouTube thumbnails at 1280×720 must stay under 2 MB and the platform re-encodes uploads to its own JPG quality regardless, so feeding it a precisely sized JPG saves a re-encode pass. (5) The Canvas drawImage path uses a Lanczos-class kernel (the same filter as Pillow's Image.Resampling.LANCZOS, which replaced the deprecated ANTIALIAS alias in Pillow 10.0.0 on 1 July 2023) — this gives you a sharper downscale than the platform's own server-side filter typically produces, so the upload renders crisper on retina displays. Centre-crop is the default; if your subject is off-centre, pre-crop the source with the aspect-ratio-crop tool first so the subject lands in the middle.

  • Instagram presets verified 2026: feed 1080×1080 / 1080×1350 / 1080×566, story + reel 1080×1920 (per help.instagram.com)
  • X (Twitter) presets: header 1500×500 (3:1), profile 400×400, in-feed post 1200×675 (16:9)
  • Facebook OG / share image 1200×630; LinkedIn personal banner 1584×396 (4:1), feed post 1200×627
  • YouTube video thumbnail 1280×720 (16:9, JPG / PNG, ≤ 2 MB per support.google.com/youtube/answer/72431)
  • Centre-crop to platform aspect ratio + Canvas drawImage with imageSmoothingQuality = 'high' (Lanczos-class kernel)
  • Live preview shows the crop window before export — pre-crop with aspect-ratio-crop if your subject is off-centre
  • Output JPG / PNG / WebP via HTMLCanvasElement.toBlob() in sRGB (IEC 61966-2-1:1999) — platform-native colour space
  • Browser-side via WHATWG Canvas — files never leave the device

Free. No signup. No file uploads. Ads via AdSense (consent required).

Sources (8)
  • WHATWG (live). HTML Living Standard — Canvas 2D Context: drawImage(). html.spec.whatwg.org/#dom-context-2d-drawimage — browser resampling mechanism that crops to platform aspect ratio then scales to platform target dimensions.
  • Duchon, C. E. (1979). Lanczos Filtering in One and Two Dimensions. Journal of Applied Meteorology, 18(8):1016-1022 (August 1979) — Lanczos resampling reference for the high-quality downscale path used when shrinking source images to platform feed/story/banner dimensions.
  • Meta Platforms (Instagram) (live). Reel size & aspect ratios on Instagram + Instagram help centre image dimensions. help.instagram.com/1038071743007909 + 2026 Instagram sizes guide instagram.com/p/DTshte0CK2z — feed square 1080×1080, portrait 1080×1350 (default since 2026), landscape 1080×566, story / reel 1080×1920 (9:16).
  • X Corp. (formerly Twitter) (live). X (Twitter) image specifications. help.x.com / business.x.com — header banner 1500×500 (3:1), profile picture 400×400 (1:1), in-feed post image 1200×675 (16:9).
  • LinkedIn Corporation (live). LinkedIn image dimension specifications. linkedin.com/help/linkedin/answer/a563309 (Pages cover 1128×191) + community-documented personal banner 1584×396 (4:1) + single-image feed post 1200×627; LinkedIn does not publish a single canonical help URL for personal banner specs.
  • Meta Platforms (Facebook) (live). Facebook sharing best practices — Open Graph image specifications. developers.facebook.com/docs/sharing/webmasters/images — Open Graph share / link preview image 1200×630 (1.91:1); minimum 600×315; ≥ 1200 wide for retina displays.
  • Google LLC (YouTube) (live). YouTube thumbnail and channel art specifications. support.google.com/youtube/answer/72431 — video thumbnail 1280×720 (16:9, JPG / GIF / PNG, ≤ 2 MB on mobile uploads / 50 MB on desktop), channel banner 2560×1440 with a 1546×423 safe area.
  • International Electrotechnical Commission (IEC) (1999). Multimedia systems and equipment — Colour measurement and management — Part 2-1: Default RGB colour space — sRGB. IEC 61966-2-1:1999 — default Canvas 2D colour space; social platforms re-encode uploads to sRGB regardless of source profile, so matching sRGB up-front avoids the platform's tone-mapping step.

These are the W3C, ISO/IEC, ITU-T, and IETF specifications the tool implements or builds on. Locate them on w3.org, iso.org, itu.int, or datatracker.ietf.org.

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