Last updated on 15 September 2026
A student searches for the meaning of a word. It typed the word into Google, stumbled upon an automatic insert, copied an approximate definition and moved on. You know the scene. The problem is not laziness, it is that he has never had a reason to go elsewhere.
Yet the great dictionaries of the French language are online, free, and some are much better than what a search engine returns. It is still necessary to know which one to open, and for what to do. Larousse and Robert do not answer the same question as the Treasure of the French Language. The Wiktionary and the Academy Dictionary do not speak the same language.
In short, Here are seven free online dictionaries, what they really do, and when to take them out to class. I have just reviewed this selection from top to bottom: two entries in the original version have disappeared, four resources have been added, and all links have been rechecked.
Table of Contents
Why an online dictionary rather than the search engine
The definition displayed directly in the search results comes from a rarely identified source, often truncated, with no example of a job or language level. It gives meaning, not use.
A dictionary tells you whether the word is familiar or supported, whether it is constructed with ‘à’ or ‘de’, how it is pronounced, since when it exists. For a student who writes, it is this information that changes something. And it’s a learning gesture, as you learn to open a paper dictionary in the right place.
1. Dico online The Robert, the most useful on a daily basis
This is the one I would recommend first if you only had one. The site offers more than 165,000 definitions written by Robert's lexicographers, about 200,000 synonyms organized by meaning, audio pronunciation of words and a complete conjugator.
The organisation of synonyms by meaning is the real differentiator: Instead of a flat list where ‘doing’ goes hand in hand with ‘doing’ and ‘making’ without hierarchy, we see families of meanings. A third-grader who seeks to vary his vocabulary in an essay finally understands why not all synonyms are equal.
The Robert also offers a space Dico in class, with downloadable resources for college and high school and the possibility to integrate the dictionary into an ENT. It is the only one on the list to have explicitly thought about the school setting.
Namely: The Le Robert editions also sell the Petit Robert, the Grand Robert and the Robert Correcteur in digital version. The site pushes these offers. The online dictionary remains free.
Link: Dico Online The Robert
2. The Larousse, the most widespread reflex
The Larousse online gives free access to 135,000 definitions, a dictionary of synonyms of 160,000 entries with 90,000 opposites, a conjugator covering more than 9,600 verbs and ten bilingual dictionaries.
It is complete, it is known to all students, and the search is fast. Two reservations anyway.
Advertising is invasive, more than its competitors, and it is frankly painful in video projection. And the educational dictionaries for ages 7-10 and 10-15, which would be of most interest to you in primary school, are reserved for the Premium offer. Free does not mean everything free.
Link: Dictionary of FrenchLarousse
3. The lexical portal of the CNRTL, to get to the bottom of things
Created in 2005 by the CNRS and backed by the ATILF laboratory, the lexical portal gives access to the Treasury of the computerized French language, i.e. 100,000 words, 270,000 definitions and 430,000 literary examples. There is also etymology, morphology, synonyms and concordance.
It is the teacher’s tool, more than the pupil’s. When you are preparing a text explanation and want to know exactly what ‘boredom’ meant in Baudelaire, this is where you have to go. Author quotes, dated and referenced, are a mine for high school.
What's new to know : After twenty years of good and loyal service, the old interface was replaced on 1 September 2026 by a new portal at portal-lexical.fr. The display is finally suitable for tablets and smartphones, and new resources have been integrated, including the Wiktionary. The old version remains accessible on cnrtl.fr for those who have their habits there.
If you had given up the CNRTL because of its austere interface, now is the time to try again.
Link: CNRTL lexical portal
4. The Dictionary of the French Academy, finally complete
This is news that has gone quite unnoticed: the 9th edition of the Dictionnaire de l’Académie française, which began in the 1980s, ended in November 2024 with the publication of the fourth volume. It has 53 000 entries, of which 21 000 words did not exist in the 8th edition of 1935.
The digital portal gives free access to the full text of this 9th edition, and also to the eight previous editions since 1694. More than 250,000 entries in total, searchable and comparable.
It is this comparison that is of great pedagogical interest. Having a class read the definition of ‘work’, ‘woman’ or ‘slave’ in 1694, 1835 and today, it is a language history session that is prepared in ten minutes. The 9th edition also adds etymological notes, a first for the Academy.
A free mobile app exists on iOS and Android.
We had devoted an article to the launch of the Academy’s digital portal at the time of its opening.
Link: Dictionary of the French Academy
5. The Wiktionary, the free dictionary
Wikipedia’s sister project now exceeds 7 million pages and offers more than 441,000 main entries for French alone. The content is licensed free, reusable, and can be copied into a class document without any rights issues.
Its particularity assumed: it is descriptive and non-normative. It describes what people say, not what should be said. This is a limit if you are looking for a standard, and a quality if you are working on language registries, regionalisms or neologisms. A word that appeared six months ago is much more likely to be there than in Larousse.
It is also the only one on this list that your students can enrich. Having an entry created or completed is a great constrained writing exercise, and the work remains visible afterwards.
Link: The Wiktionary
6. The desire of CRISCO, for synonyms
The CRISCO Laboratory’s Electronic Dictionary of Synonyms at the University of Caen Normandie offers more than 50 000 entries and 209 000 synonymic relationships. It receives around 150 000 requests per day, mostly from teachers and academics.
What he does best than the others: it classifies synonyms by proximity of meaning and offers a graphic representation of word families. It can be seen at a glance that ‘clear’ does not play in the same family depending on whether one is talking about a water, an explanation or a colour. Each word refers to its definition in TLFi.
No advertising, no inscription, a slightly dated interface but perfectly readable in video projection.
Link: Electronic dictionary of synonyms
7. Usito, North American French
For our Quebec readers, it is the reference dictionary, from primary school to university. For teachers in France and Belgium, it is an excellent medium for working on the variation of French: Comparing the same entry in Usito and Robert shows concretely that there is no French but French, all legitimate.
We had dedicated to him a dedicated article.
Link: Usito
Which English Dictionary to Choose According to Need
| Looking for … | Open … |
|---|---|
| A clear definition, quickly, with a student | Dico Online The Robert |
| A precise synonym for a writing | The Desire of CRISCO |
| An author’s quote, a nuance of meaning | The lexical portal (TLFi) |
| The history of a word, the evolution of a definition | Dictionary of the French Academy |
| A very recent word, regionalism, slang | The Wiktionary |
| A Quebec or North American use | Usito |
| The conjugation of a verb | Larousse or The Robert |
Before putting it in the hands of the students
Three reflexes, valid for any of these sites.
Test the display on the class material. A legible dictionary on your desktop screen can become unreadable at the back of the room. CRISCO and the lexical portal go well in video projection, the sites loaded with advertising much less.
Check the advertisement before the session. Some of these sites fund their free use through display advertising, and you are not in control of what will be displayed. A glance the day before avoids a bad surprise in front of thirty students.
See if an account is requested. None of these seven dictionaries require registration for simple consultation, but some ancillary functions require one. Creating accounts for underage students on a third-party service is never trivial, so avoid it when you can do without it.
To go further
These seven resources deal with French. If your need is bilingual or multilingual, look at the WordReference and Glosbe, or from our selection of Best Online Translation Sites.
To explore the diversity of French in the world, the Dictionary of Francophones It's worth the detour.
And if the goal is to advance your students in spelling rather than having them look for definitions, Dictaly offers free online dictations, while Scribens and Antidote intervene at the proofreading stage.
Frequently asked questions
What is the best free online dictionary in English?
For everyday use with students, the online Dico Le Robert is the most complete and best organized, thanks to its synonyms classified by meaning. For more in-depth work on language, the CNRTL lexical portal and the Dictionnaire de l’Académie française go much further.
Are these online English dictionaries really free?
The consultation is open for all seven. Attention should be paid, however, to additional offers: Larousse’s educational dictionaries for 7-15 year-olds are part of a premium paid formula, and Le Robert markets its digital versions of Le Petit and Le Grand Robert separately.
Can they be used with primary school students?
Yes, but with an accompaniment. The Wiktionary and TLFi are too clumsy for young readers. The Robert and the Larousse remain the most accessible. In primary school, the real question is less the choice of the dictionary than the learning of the search gesture itself.
Has the CNRTL changed its address?
The lexical portal was replaced on 1 September 2026 by a new version accessible on portal-lexical.fr, with a mobile-friendly interface and new resources. The old version is still available on cnrtl.fr.
English
Hello,
personally I work a lot with CNRTL… extremely complete!
The TLF (Treasury of the French Language) seems interesting to me despite its complexity even for beginners because its simplified phonetic keyboard makes it possible to search for a word according to its pronunciation.
You can also use the megadictionary of the French language, downloadable in pdf.
The Robert's Online Dictionary (https://dictionnaire.lerobert.com) has the advantage of meeting all needs (definitions, synonyms, conjugation, pronunciation, … grammar), and of being regularly updated. Synonyms are grouped according to their meaning, which saves a lot of time.