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HTML Encode/Decode

Convert all applicable characters to HTML entities, or vice versa

Tags: decoder encoder html html encode/decode

🚀 315,090 total conversions (41 this month)

Practice Python with coding challenges

Solve hands-on problems right in this editor: run the sample tests, submit, and get an AI code review.

All Python challenges
Easy

Average of Three

Average three whole numbers.

You'll learn ArithmeticDivision
BeginnerLearning-pathVariables
Python C++ C#
1 solved
View solutions (1)
Easy

Rectangle Perimeter

Compute the perimeter of a rectangle from its sides.

You'll learn ArithmeticReturn values
BeginnerLearning-pathVariables
Python C++ C#
1 solved
View solutions (1)
Medium

One Generation of a Genetic Algorithm

Breed the next generation of bit strings with tournament selection, single-point crossover and mutation.

You'll learn Genetic algorithmsEvolutionary search
OptimizationSimulationai
Python C++ C#
0 solved
No solutions yet
Easy

Epsilon-Greedy Multi-Armed Bandit

Balance exploration and exploitation on a multi-armed bandit with epsilon-greedy action selection.

You'll learn Explore vs exploitBandits
Reinforcement learningaimachine learning
Python C++ C#
0 solved
No solutions yet
Easy

Markov Chain State Distribution

Propagate a probability distribution through a Markov chain's transition matrix for a number of steps.

You'll learn Markov chainsProbability
Simulationaimath
Python C++ C#
0 solved
No solutions yet
Medium

Value Iteration

Compute how valuable each state of a Markov decision process is by repeatedly applying the Bellman optimality update.

You'll learn Bellman equationMDPs
Reinforcement learningaimachine learning
Python C++ C#
0 solved
No solutions yet
Medium

Q-Learning Updates

Apply the Q-learning update to a stream of experiences and watch rewards flow back to earlier states.

You'll learn Q-learningDiscounted rewards
Reinforcement learningaimachine learning
Python C++ C#
0 solved
No solutions yet
Medium

Alpha-Beta Pruning

Evaluate a game tree with minimax and alpha-beta pruning, and count how many leaves the search really looks at.

You'll learn Alpha-beta pruningGame search
RecursionTreesai
Python C++ C#
0 solved
No solutions yet
Medium

Minimax Tic-Tac-Toe

Pick the perfect tic-tac-toe move by searching the whole game tree with minimax.

You'll learn MinimaxGame trees
Recursionai
Python C++ C#
0 solved
No solutions yet
Medium

A* Search on a Weighted Grid

Find the cheapest path across a grid of terrain costs with A*, the search algorithm behind game and robot pathfinding.

You'll learn A* searchHeuristics
GraphsGridsShortest-pathai
Python C++ C#
0 solved
No solutions yet
Medium

Temperature and Top-K Sampling

Choose the next token like a language model does: keep the top k logits, apply temperature, and sample.

You'll learn Text generationSampling
aimachine learning
Python C++ C#
0 solved
No solutions yet
Hard

Multi-Head Self-Attention

Project the input into queries, keys and values, run attention in several heads in parallel, and combine them.

You'll learn Multi-head attentionMatrix projections
aimachine learning
Python C++ C#
0 solved
No solutions yet

Introduction

This online HTML encoder tool helps you convert characters into HTML entities. It’s a simple and efficient way to handle reserved or special characters in your HTML code.

How to Use This Tool

  1. Paste your HTML code directly into the editor or type it in.
  2. Click the Encode or Decode button to process your HTML.
  3. After encoding or decoding, you can:
    • Download the processed result.
    • Save or share it using a unique link.
    • Sign in with Google or GitHub to save your results for future use.

What is an HTML Entity?

An HTML entity is a piece of text that starts with an ampersand (&) and ends with a semicolon (;). Entities are commonly used to display reserved characters, like < or >, which would otherwise be interpreted as HTML code. They can also represent invisible characters (e.g., non-breaking spaces) or special characters that are difficult to type on a standard keyboard.

For example:

  • < represents the less-than symbol ("<").
  • & represents the ampersand ("&").

Learn more about HTML entities from this helpful guide .

Some Useful HTML Character Entities

Result Description Entity Name Entity Number
non-breaking space &nbsp; &#160;
< less than &lt; &#60;
> greater than &gt; &#62;
& ampersand &amp; &#38;
" double quotation mark &quot; &#34;
' single quotation mark (apostrophe) &apos; &#39;
¢ cent &cent; &#162;
£ pound &pound; &#163;
¥ yen &yen; &#165;
€ euro &euro; &#8364;
© copyright &copy; &#169;
® registered trademark &reg; &#174;

Examples

Before encoded

      
<!doctype html>
<html lang="en">
  <head>
    <title>Hello World!</title>
  </head>
  <body>
    <div id="content">
      <h1 class="title">Hello World!</h1>
    </div>
  </body>
</html>

After encoded

      
&lt;!doctype html&gt;
&lt;html lang=&quot;en&quot;&gt;
  &lt;head&gt;
    &lt;title&gt;Hello World!&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
    &lt;div id=&quot;content&quot;&gt;
      &lt;h1 class=&quot;title&quot;&gt;Hello World!&lt;/h1&gt;
    &lt;/div&gt;
  &lt;/body&gt;
&lt;/html&gt;