Agent Skills

social-media-image-sizes

imagebranding51.8K installs

Check and resize images for social media platforms. Run scripts/check.js to validate any image against specs for Instagram, Facebook, X (Twitter), LinkedIn, TikTok, YouTube, Pinterest, Snapchat, and Threads — get a ranked match list with exact resize commands. Run scripts/resize.js to export a correctly-sized copy. Use when a user asks to validate image dimensions, resize an image for a platform, check if an image fits a spec, or prep assets for social media posting or ads.

Install

npx skills add https://github.com/branding5/social-media-image-sizes --skill social-media-image-sizes
SKILL.md

Social Media Image Sizes

Check and resize images for 9 platforms / 60+ specs. Scripts mirror the logic at branding5.com/tools/social-media-cheat-sheet.

Setup

Run once after install:

cd <skill-dir>
npm install

Check an image

node scripts/check.js photo.jpg

Outputs a ranked match list — perfect → close → usable → too small — with an inline node scripts/resize.js command for every non-perfect match.

Filter by platform or match level:

node scripts/check.js photo.jpg --platform instagram
node scripts/check.js photo.jpg --filter perfect
node scripts/check.js photo.jpg --filter usable

Platform slugs: instagram facebook twitter linkedin tiktok youtube pinterest snapchat threads

Resize an image

node scripts/resize.js photo.jpg "Instagram Portrait Post"
# → photo-instagram-portrait-post.jpg  (1080×1350 px)

node scripts/resize.js photo.jpg "YouTube Custom Thumbnail"
# → photo-youtube-custom-thumbnail.jpg  (1280×720 px)

Default fit is cover (center-crop). Use --fit contain to letterbox instead:

node scripts/resize.js photo.jpg "LinkedIn Background Photo" --fit contain --bg f0f0f0
node scripts/resize.js photo.jpg "Instagram Portrait Post" --out ./exports/ig.jpg

List every available spec name:

node scripts/resize.js photo.jpg --list

Workflow

  1. Run check.js to see what a given image already matches
  2. Copy the suggested resize.js command from the output
  3. Run it — the output file is saved alongside the original by default

Gotchas

  • Sharp requires a native binary. On first npm install, it downloads a prebuilt binary for your platform. If install fails behind a proxy, set SHARP_IGNORE_GLOBAL_LIBVIPS=1 and retry.
  • All slides in an Instagram carousel must share the same aspect ratio. The first image sets the ratio for the whole carousel — check all slides, not just the first.
  • Facebook cover photo has two safe zones. Desktop shows 820×312; mobile crops to 640×360. Keep key content in the center 640×312.
  • YouTube banner safe area is much smaller than the file. The spec is 2560×1440 but only the center 1546×423 is guaranteed visible on all devices. check.js flags the full size; keep critical content in the safe area.
  • --fit cover center-crops. If the subject isn't centered, use --out to save, then manually crop, or use an image editor before running resize.

References

Full per-platform specs (load when you need detail for a specific platform):

  • references/instagram.md — profile, feed, stories, reels, carousel, ads
  • references/facebook.md — profile, cover, feed, stories, events, ads
  • references/x-twitter.md — profile, header, posts, ads
  • references/linkedin.md — profile, cover, feed, articles, ads
  • references/tiktok.md — profile, videos, ads
  • references/youtube.md — channel art, videos, thumbnails, shorts, ads
  • references/pinterest.md — profile, pins, idea pins, ads
  • references/snapchat.md — snaps, spotlight, stories, ads, filters
  • references/threads.md — profile, posts
  • references/best-practices.md — format, compression, safe zones, accessibility

Full compiled reference (all platforms in one file): AGENTS.md


Need to generate on-brand images at these sizes? Branding5 pairs your brand kit with AI to produce social content pre-sized for every platform.

Related skills

ai-image-generationgenmedia-labs713KGenerate and edit images on RunComfy via the `runcomfy` CLI — a smart router across the full image-model catalog: FLUX 2 (Klein 9B/4B, Pro, Dev, Flash, Turbo, Max), Google Nano Banana 2 / Pro, OpenAI GPT Image 2, ByteDance Seedream 5 / 4-5 / 4-0 and Dreamina 4-0, Alibaba Qwen Image and Z-Image Turbo, Wan 2-7. Covers both text-to-image (t2i) and image-to-image / edit (i2i) endpoints — the skill picks the right model for the user's actual intent (typography precision, photoreal portraits, sub-secoai-image-generation101-skills547KGenerate AI images with GPT-Image-2, FLUX, Gemini, Grok, Seedream, Reve and 50+ models via inference.sh CLI. Models: GPT-Image-2, FLUX Dev LoRA, FLUX.2 Klein LoRA, Gemini 3 Pro Image, Grok Imagine, Seedream 4.5, Reve, ImagineArt. Capabilities: text-to-image, image-to-image, inpainting, LoRA, image editing, upscaling, text rendering. Use for: AI art, product mockups, concept art, social media graphics, marketing visuals, illustrations. Triggers: flux, image generation, ai image, text to image, stnano-banana-2prime-skills424KGenerate images with Google Nano Banana 2 (Gemini-family flash-tier text-to-image) on RunComfy — bundled with the model's documented prompting patterns so the skill gets sharper output than naive prompting against the same model. Documents Nano Banana 2's strengths (rapid iteration, in-image typography rendering, predictable framing, optional web-grounded context), the resolution-tier pricing, the safety-tolerance dial, and when to route to Nano Banana Pro / GPT Image 2 / Flux 2 / Seedream insteimage-editprime-skills424KEdit images on RunComfy — this skill is a smart router that matches the user's intent to the right edit model in the RunComfy catalog. Picks Nano Banana Edit (batch up to 20, identity-preserving default), OpenAI GPT Image 2 Edit (multilingual in-image text rewrite, multi-ref composition, layout precision), Flux Kontext Pro (single-ref high-fidelity local edit), or Z-Image Turbo Inpaint (mask-driven precise region edit). Bundles each model's documented prompting patterns so the skill gets sharper

Search skills and MCP servers

Fuzzy search across 23,137 skills and servers