What scale does it use?

One six-step scale for every language, aligned with the CEFR levels A1 to C2 used in language teaching. Each passage is judged on how hard it is to understand, not on syllable counts, so it works beyond English.

Can it make text harder?

Yes. Pick the expert level and plain text becomes more precise and compact for specialists.

Does every passage change?

No. Passages already at the level you set stay word for word.

Reading level converter

Pick a level. Get the same text at that level.

Set the reading level your reader has, from very simple (A1) to expert (C2). The reading level converter rewrites only the passages above it, explains the terms that stay, and can go up as well as down.

Make it readable

6 free pages a month. No card.

Complex text becomes larger, simpler lettering.

Made for

Teaching material for a class at one level
Public information that has to reach everyone
Expert text made more compact for specialists

Before and after

Example: 29 → 45 words · 1 term explained · every fact kept

Original

Photosynthesis is the process by which chlorophyll-containing organisms convert light energy into chemical energy, synthesizing glucose from carbon dioxide and water while releasing oxygen as a by-product.

Result

Plants and other living things with chlorophyll (the green substance in leaves) make their own food from light. This is called photosynthesis.

They take carbon dioxide and water and turn them into a sugar called glucose.

Oxygen is left over, and they give it off.

Kept: carbon dioxide
Kept: water
Kept: glucose
Kept: oxygen
Explained: chlorophyll

How Simplify works

Step 01
Every passage is rated
On one six-step scale for every language, from very simple to expert, and checked for unexplained terms and instructions that read two ways.
Step 02
Only hard passages change
Passages already at your reader's level stay word for word.
Step 03
Terms are explained, not removed
A term the reader will meet elsewhere stays, with a short plain explanation the first time.
Step 04
Meaning is checked
Every must, may, unless, deadline and number has to survive, or the passage keeps its original words.

Options

Reader: General audience, customers, patients, second-language readers, young readers, newcomers, decision-makers or specialists, or describe your own.
Level: Very simple (A1) to expert (C2); simpler or more precise.
Write in: Keep the language, or translate while simplifying.

From code, terminal or agent

# REST API
curl https://readable.md/api/v1/transform \
  -H "Authorization: Bearer $READABLE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "tool": "simplify", "text": "…", "level": 1 }'

# Command line
readable simplify worksheet.md --level 1

# MCP tool: simplify

API, MCP and CLI docs

Questions

What scale does it use?: One six-step scale for every language, aligned with the CEFR levels A1 to C2 used in language teaching. Each passage is judged on how hard it is to understand, not on syllable counts, so it works beyond English.
Can it make text harder?: Yes. Pick the expert level and plain text becomes more precise and compact for specialists.
Does every passage change?: No. Passages already at the level you set stay word for word.