This document lists the HTML codes that are permissible in Canvas. When creating custom HTML coding in Canvas, certain HTML codes do not work upon saving. This is because Canvas only supports certain HTML elements for security reasons. This also applies to content copied and pasted from an external source.
Allowed HTML Tags
a, acronym, address, area, article, aside, audio, b, bdo, big, blockquote, br, caption, cite, code, col, colgroup, dd, del, details, dfn, div, dl, dt, em, embed, footer, h2, h3, h4, h5, h6, header, hr, i, img, ins iframe, kbd, legend, li, map, nav, object, ol, p, param, picture, pre, q, ruby, rp, rt, samp, section, small, span, strike strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, time, tr, track, tt, u, ul, var, video
MathML tags
annotation, annotation-xml, maction, maligngroup, malignmark, math, menclose, merror, mfenced, mfrac, mglyph, mi, mlabeledtr, mlongdiv, mmultiscripts, mn, mo, mover, mpadded, mphantom, mprescripts, mroot, mrow, ms, mscarries, mscarry, msgroup, msline, mspace, msqrt, msrow, mstack, mstyle, msub, msubsup, msup, mtable, mtd, mtext, mtr, munder, munderover, none, semantics, mark
Allowed Attributes on HTML Elements
all elements allow style, class, id, title, role, lang, dir
Element | Allowed Attribute(s) |
|---|
a | href, target, name |
abbr | title |
area | alt, coords, href, shape, target |
aria | labelledby, atomic, busy, controls, describedby, disabled, dropeffect, flowto, grabbed, haspopup, hidden, invalid, label, labelledby, live, owns, relevant, autocomplete, checked, disabled, expanded, haspopup, hidden, invalid, label, level, multiline, multiselectable, orientation, pressed, readonly, required, selected, sort, valuemax, valuemin, valuenow, valuetext |
audio | name, src, muted, controls |
blockquote | cite |
col | span, width |
colgroup | span, width |
embed | allowfullscreen, allowscriptaccess, height, name, pluginspage, src, type, width, wmode |
font | face, color, size |
img | align, alt, height, src, title, usemap, width |
iframe | src, width, height, name, align, allowfullscreen |
map | name |
object | classid, codebase, data, height, type, width |
ol | start, type |
param | name, value |
q | cite |
source | Height, media, sizes, src, srcset, type, width |
table | summary, width, border, cellpadding, cellspacing, center, frame, rules |
tr | align, valign, dir |
td | abbr, axis, colspan, rowspan, width, align, valign, dir |
th | abbr, axis, colspan, rowspan, width, align, valign, dir, scope |
ul | type |
video | name, src, allowfullscreen, muted, poster, width, height, controls, playsinline |
Allowed protocols for some elements
ftp, http, https, mailto
http, https
- blockquote cite
- img src
- q cite
- object data
- embed src
- iframe src
- style any
skype
Allowed style properties
background, border, border-radius, clear, color, cursor, direction, display, flex, float, font, grid, height, left line-height, list-style, margin, max-height, max-width, min-height, min-width, overflow overflow-x, overflow-y, padding, position, right, text-align, table-layout text-decoration, text-indent, top, vertical-align, visibility, white-space, width z-index, zoom
This resource can also be accessed from the following Canvas Guides: