Design, manage, and roll out branded email signatures across a whole company.
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What it is
Byline is a web app for creating polished, on-brand email signatures and pushing them out to entire teams. Admins design a template once, manage brand profiles across multiple domains, and roll changes out to everyone at once — complete with vCards, QR codes, and public profile links.
Why it exists
Email signatures are everywhere and almost always inconsistent — people hand-edit them, brands drift, and there's no audit trail. Byline centralizes the whole thing so a company's signatures stay consistent, compliant, and instantly updatable.
Who it's for
IT administrators and brand teams managing anywhere from ten to a thousand-plus people.
Standout features
What you design is what they see
Signatures export with every icon as an image and nothing email clients choke on, plus a ready-made file for Outlook, so they render the same in Outlook, Gmail, and Apple Mail.
Animated signature images
Crossfade, zoom, slide, or dissolve between two images. The server renders a sharp, transparent animated GIF for email while the editor previews it live.
Company-controlled signatures
Admins publish shared designs where each field is free text, a personal value, or a company value, and can lock fields so staff only fill in their own details.
Many brands, one account
Each verified domain gets its own logo, colors, template, and links, and people can keep a separate profile per brand. A blank value hides the field instead of leaking another brand's.
Digital business cards
A public card page per person and per brand, kept in sync with the signature, with a QR code that either shares the link or saves the contact straight to a phone.
Click tracking that respects privacy
Opt-in link tracking with hashed visitor data, duplicate clicks collapsed, and bots and email-security scanners filtered out so the numbers reflect real people.
Built for teams
Multi-factor sign-in that an organization can require, per-organization password policy, and lockout after repeated failed attempts.
AI powers Byline's help, not its signatures: an assistant answers questions in the app and on the website, and hands off to a human when it should.
Anthropic Claude by default; OpenAI and Google Gemini selectable
Support and sales assistant
Streaming chat answers product questions in the app and on the public site. When it can't help, it escalates: the full transcript goes to support, ready for a one-click reply to the customer.
Configurable and versioned
Admins choose the provider and model per chat area, and every prompt change is versioned with diff and one-click revert. With no key configured, chat falls back to a feedback form.
Watches its own model
A daily check confirms the configured model still exists and alerts the team before a provider retirement can break chat.
How it works
Build activity
Active this monthLast update Sep 29, 2026 · 43 changes in the last 90 days
Updated automatically from the project's build history. Last refreshed Oct 12, 2026.
What made it interesting to build
Rolling signatures out reliably at scale was the hard part. A notable rework involved how contact-card photos were embedded — switching to inline image data so a saved vCard always renders, even offline. Validating custom domains brought a long tail of edge cases around DNS that had to be handled gracefully rather than failing silently.