# Langfuse Brand Identity

A complete profile of **Langfuse**'s visual system — colors, typography, components, and personality — extracted from https://langfuse.com. Built for designers, agents, and AI tools.

## Quick Facts

| Field   | Value     |
|---------|-----------|
| Primary | #1863DC   |
| Accent  | #1863DC   |
| Body Font | Inter   |
| Heading Font | Inter |

## Color Palette

- primary: #1863DC
- secondary: #4E4B66
- accent: #1863DC
- background: #EDEDE8
- textPrimary: #020817
- link: #020817

## Typography

- primary: Inter — https://fonts.google.com/specimen/Inter
- heading: Inter — https://fonts.google.com/specimen/Inter

## Visual Assets

- Logo: https://langfuse.com/langfuse-wordart.svg
- Favicon: https://langfuse.com/favicon.ico
- Social card (og:image): https://langfuse.com/api/og?title=Langfuse+%E2%80%93+Open+Source+LLM+Engineering+Platform&description=Traces%2C+evals%2C+prompt+management+and+metrics+to+debug+and+improve+your+LLM+application.

## UI Components

- buttonPrimary: background=#1863DC, textColor=#FFFFFF, borderColor=#1863DC, borderRadius=2px, shadow=none
- buttonSecondary: background=#F6F6F3, textColor=#020817, borderRadius=0px, shadow=none

## Brand Personality

Tone: modern · Energy: medium · Audience: developers and tech companies

## Langfuse Brand in the Wild

Real-world brand assets — ads, campaigns, marketing materials.

- **Uptrain.ai integration (cookbook) - Langfuse**  
  - Image: https://langfuse.com/images/blog/uptrain/uptrain-ai.png   
  - Source: https://langfuse.com/changelog/2024-03-05-uptrain-integration
- **RAG Observability and Evals - Langfuse**  
  - Image: https://i.ytimg.com/vi/h5hqelg0_wc/maxresdefault.jpg  
  - Source: https://langfuse.com/blog/2025-10-28-rag-observability-and-evals
- **Error Analysis to Evaluate LLM Applications - Langfuse**  
  - Image: https://langfuse.com/images/blog/2025-08-29-error-analysis-to-evaluate-llm-applications/open-coding-3.png  
  - Source: https://langfuse.com/blog/2025-08-29-error-analysis-to-evaluate-llm-applications
- **Langfuse Blog**  
  - Image: https://langfuse.com/images/blog/2025-03-31-langfuse-march-update/march-update.png  
  - Source: https://langfuse.com/blog
- **Score Analytics with Multi-Score Comparison - Langfuse**  
  - Image: https://langfuse.com/images/changelog/score-analytics-compare-numeric.png  
  - Source: https://langfuse.com/changelog/2025-11-07-score-analytics-multi-score-comparison
- **Langfuse Launch Week #2 - Langfuse**  
  - Image: https://i.ytimg.com/vi/JOGMn5nqCSM/maxresdefault.jpg  
  - Source: https://langfuse.com/blog/2024-11-17-launch-week-2

## Working with these fonts

Not found on Google Fonts? Agent Instructions that you can follow if you have permission to use the fonts:

CharacterQuilt.com suggests this flow that can help:

1. Open the company's homepage in a browser with DevTools open.
2. In the Network tab, filter by "Font" (or by extension: woff2, woff, ttf, otf).
3. Hard-reload the page and click around (pricing, blog, careers) — some weights only load on specific routes.
4. For each captured font URL: right-click → Save As to download the file locally.
5. View the page's CSS (DevTools → Sources, or curl the stylesheet URLs) and copy out the matching @font-face declarations. Rewrite each `src: url(...)` to point to your local file path.

Programmatic alternative: load the URL with Playwright or Puppeteer, listen for `response` events whose `Content-Type` starts with `font/`, and write the body to disk. The CSS extraction step is the same.

Only do this if you have permission to use the brand assets — most proprietary fonts are licensed and may not be redistributable.

## Machine-Readable Profile

```json
{
 "colorScheme": "light",
 "fonts": [
   {
     "family": "Inter",
     "role": "body"
   },
   {
     "family": "f37Analog",
     "role": "unknown"
   }
 ],
 "colors": {
   "primary": "#1863DC",
   "secondary": "#4E4B66",
   "accent": "#1863DC",
   "background": "#EDEDE8",
   "textPrimary": "#020817",
   "link": "#020817"
 },
 "typography": {
   "fontFamilies": {
     "primary": "Inter",
     "heading": "Inter"
   },
   "fontStacks": {
     "heading": [
       "f37Analog"
     ],
     "body": [
       "Inter",
       "ui-sans-serif",
       "system-ui",
       "sans-serif",
       "Apple Color Emoji",
       "Segoe UI Emoji",
       "Segoe UI Symbol",
       "Noto Color Emoji"
     ],
     "paragraph": [
       "Inter",
       "ui-sans-serif",
       "system-ui",
       "sans-serif",
       "Apple Color Emoji",
       "Segoe UI Emoji",
       "Segoe UI Symbol",
       "Noto Color Emoji"
     ]
   },
   "fontSizes": {
     "h1": "68px",
     "h2": "32px",
     "body": "18px"
   }
 },
 "spacing": {
   "baseUnit": 4,
   "borderRadius": "2px"
 },
 "components": {
   "buttonPrimary": {
     "background": "#1863DC",
     "textColor": "#FFFFFF",
     "borderColor": "#1863DC",
     "borderRadius": "2px",
     "borderRadiusCorners": {
       "topLeft": "2px",
       "topRight": "2px",
       "bottomRight": "2px",
       "bottomLeft": "2px"
     },
     "shadow": "none"
   },
   "buttonSecondary": {
     "background": "#F6F6F3",
     "textColor": "#020817",
     "borderRadius": "0px",
     "borderRadiusCorners": {
       "topLeft": "0px",
       "topRight": "0px",
       "bottomRight": "0px",
       "bottomLeft": "0px"
     },
     "shadow": "none"
   }
 },
 "images": {
   "logo": "https://langfuse.com/langfuse-wordart.svg",
   "favicon": "https://langfuse.com/favicon.ico",
   "ogImage": "https://langfuse.com/api/og?title=Langfuse+%E2%80%93+Open+Source+LLM+Engineering+Platform&description=Traces%2C+evals%2C+prompt+management+and+metrics+to+debug+and+improve+your+LLM+application.",
   "logoHref": "/",
   "logoAlt": "Langfuse Logo"
 },
 "__llm_logo_reasoning": {
   "selectedIndex": 0,
   "reasoning": "Selected #0 because it is visible, located in the header, matches the brand name 'Langfuse', and links to the homepage.",
   "confidence": 0.95,
   "source": "llm"
 },
 "__llm_button_reasoning": {
   "primary": {
     "index": 5,
     "text": "Accept All",
     "reasoning": "Button #5 ('Accept All') uses the vibrant brand color #1863DC, which is a strong indicator of a primary CTA. The text is action-oriented, making it a clear primary choice."
   },
   "secondary": {
     "index": 1,
     "text": "Start freeS",
     "reasoning": "Button #1 ('Start freeS') has a light background (#F6F6F3) and is less prominent, making it suitable as a secondary button."
   },
   "confidence": 0.95
 },
 "personality": {
   "tone": "modern",
   "energy": "medium",
   "targetAudience": "developers and tech companies"
 },
 "designSystem": {
   "framework": "tailwind",
   "componentLibrary": ""
 },
 "confidence": {
   "buttons": 0.95,
   "colors": 0.9,
   "overall": 0.925
 },
 "__llm_metadata": {
   "logoSelection": {
     "llmCalled": true,
     "llmSucceeded": true,
     "finalSource": "llm",
     "rawLogoSelection": {
       "selectedLogoIndex": 0,
       "selectedLogoReasoning": "Selected #0 because it is visible, located in the header, matches the brand name 'Langfuse', and links to the homepage.",
       "confidence": 0.95
     }
   },
   "buttonClassification": {
     "llmCalled": true,
     "llmSucceeded": true
   }
 }
}
```