Free Tool

Rich Text Preview Tool

Paste textRuns JSON or type richText Markdown — see a live preview, switch between formats, and copy the output for your API calls.

Examples:

richText (Markdown)

Preview

DRUGNAME®
Active ingredient: loratadine 10 mg
Dosage: 25 mg/m
2 body surface area

Equivalent textRuns JSON

[
  {
    "text": "DRUGNAME",
    "bold": true
  },
  {
    "text": "®",
    "superscript": true
  },
  {
    "text": "\n"
  },
  {
    "text": "Active ingredient: ",
    "color": "#666666"
  },
  {
    "text": "loratadine 10 mg",
    "bold": true
  },
  {
    "text": "\nDosage: 25 mg/m"
  },
  {
    "text": "2",
    "superscript": true
  },
  {
    "text": " body surface area"
  }
]

Syntax Reference

richText Markdown Syntax
SyntaxResult
**text**Bold
*text*Italic
__text__Underline
~~text~~Strikethrough
{sup}text{/sup}Superscript
{sub}text{/sub}Subscript
{color:#hex}text{/color}Colored text
{hl:#hex}text{/hl}Highlighted text
{font:Name}text{/font}Custom font
textRuns JSON Structure
[
  {
    "text": "Bold text",
    "bold": true
  },
  {
    "text": "®",
    "superscript": true
  },
  {
    "text": "Colored",
    "color": "#2563eb"
  },
  {
    "text": "H",
    "fontSize": 24
  },
  {
    "text": "2",
    "subscript": true,
    "fontSize": 24
  },
  {
    "text": "O",
    "fontSize": 24
  }
]

Need Dynamic Image Generation?

RenderStack renders images from templates with full rich text support via API. Design once, generate thousands of images with inline formatting.

Frequently Asked Questions