Create a timeline

A browser-first timeline maker

tlmkr builds layered timelines out of events that can last a day or a decade. Timelines are saved in this browser by default. If you choose, you can connect GitHub and commit selected timelines to a repository you control; timelines you do not select stay local.

What you can do with it

• Layers keep parallel stories apart

  Each team, workstream, or storyline gets its own lane, so overlapping work reads as overlapping instead of collapsing into one crowded row.

• Events span time, not just points

  An event can sit on a single day or stretch across years. Drag either edge to change how long it runs, or drag the middle to move the whole thing.

• One view, from a week to a century

  Zoom and pan to any stretch of time. The timeline refits itself to whatever range you land on, so a sprint and a dynasty get the same treatment.

• Export as PNG, SVG, or JSON

  Take an image into a deck, an SVG into a design tool, or the raw JSON into your own scripts. You can also print the timeline straight from the browser.

• Undo and redo every edit

  Every change is reversible with ⌘Z, including deleting a whole timeline. Press ? at any point for the full list of keyboard shortcuts.

• Bring events you already have

  Import a JSON file directly, or copy a ready-made prompt into ChatGPT, Claude, or Gemini, and paste the events it writes back into the timeline.

• Optional backups in your GitHub repository

  Connect GitHub, choose a repository, and select exactly which timelines to commit. Remote changes are always shown for review before they affect this browser.

Timeline templates

Each template opens a working timeline with its layers and events already in place, dated around today, so you can rename things instead of starting from an empty canvas.

• Product roadmap timeline templateWorkstreams across a year, one lane per team.
• Project plan timeline templateA single project broken into phases with a review gate.
• Personal history timeline templateLong spans across decades, for a life or a company story.

Common questions

Is tlmkr free?

Yes. There is nothing to install and you can start without an account. A GitHub account is only needed if you choose to sync selected timelines to your own repository.

Does my timeline leave my browser?

Only when you choose. Creating a share link uploads that one timeline for a day. Connecting GitHub sends only the timelines you explicitly select to the repository you choose. Other timelines stay in this browser.

What can I export?

PNG for slides and documents, SVG for design tools, and JSON for the complete timeline as structured data. You can also print directly from the browser.

How does sharing work?

Sharing creates a short read-only link that expires one day later. Whoever opens it sees a copy and cannot change yours. After a day the link stops working and the stored copy is gone.

Can I import events I already have?

Yes. tlmkr reads a JSON file of events, and it can also write a prompt for ChatGPT, Claude, or Gemini describing the format, so an assistant can draft the events for you to paste in.

What happens if I clear my browser data?

Clearing site data removes this browser’s working copies. Export important timelines as JSON or commit selected timelines to GitHub first so you can restore them later.