Email Signature Logo: Size, Format & Hosting Best Practices

Add a sharp, reliable logo to your email signature without broken images in Gmail or Outlook.

A broken logo is worse than no logo. Email clients block local files and strip some image formats — your logo must be hosted at a public HTTPS URL with explicit width attributes.

Logo specs that work

Format: PNG with transparent background (or JPG for photos)
Display width: 100–150 px (upload 2x for retina)
File size: under 50 KB
Hosted URL: https:// on your domain or CDN
Always set width and height in HTML

Image size guide · Signature size limits · Common mistakes

Add logo in ProSignature

Upload your logo in the email signature generator — it hosts images and outputs client-safe HTML. Or use Quick Start from website to pull your logo automatically.

Tutorial

How to Create a Professional Email Signature (2026 Guide)

A complete step-by-step guide to creating a professional email signature that works in every major email client.

Tips & Tricks

Professional Email Signature Examples (9 Templates)

Nine professional email signature examples — minimal, corporate, creative — ready to customize and export.

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How to Add an Email Signature in Gmail (Step-by-Step)

Add a professional HTML email signature to Gmail on desktop and mobile without breaking layout or images.

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