Irish
- Before
- Feicim mo cat.
- After
- Feicim mo chat.
The possessive mo triggers lenition: cat becomes chat.
Your browser. Your language.
Blas underlines likely spelling, grammar, mutation, punctuation, and style issues as you type, then lets you accept a suggestion without leaving the page.
Chrome and Firefox are released. Safari for Mac has a build approved for distribution; iPad verification is still in progress.
Live, local rules
Edit the text, inspect a suggestion and accept or dismiss it. This demo covers Irish and Welsh mutations, not every check in the extension.
Example: Feicim mo cat. — edit it or write your own.
Loading local rules…
Your text stays in this browser. The demo downloads language data and uses the website's local mutation checker; the extension has a separate, broader checking pipeline.
Your assumptions, not a benchmark
Choose how much you write and how much review time you expect to avoid. This is an illustrative calculation, not a measured productivity claim.
Assumes 4 minutes saved per 1,000 characters and 5 writing days per week.
Actual savings may be zero or negative if checking suggestions takes longer than reviewing alone. The checker does not replace proofreading.
Two mutation examples you can also try in the editor above. They illustrate supported rules, not exhaustive grammar coverage.
The possessive mo triggers lenition: cat becomes chat.
The possessive fy triggers nasal mutation: car becomes nghar.
What it catches
Mutations
Selected patterns for Irish and Welsh initial mutations, including common séimhiú, urú, t-prefix, soft, nasal, and aspirate cases.
Case + agreement
Selected patterns for genitives, noun and adjective agreement, and common verb agreement mistakes.
Béarlachas
A bounded set of Irish phrases that mirror English where a more natural Irish expression is known.
Copula vs. tá
Common learner mistakes involving the Irish copula and tá, with a suggested correction when the pattern is clear.
Typography + punctuation
Capitalisation, repeated punctuation, doubled words and spaces, commas, and other common writing mechanics.
Style warnings
Selected wordy phrases, long sentences, and repeated words. Suggestions, not demands.
Write in the places you already use. Blas checks supported text fields in Chrome, including common email, chat, social, and document editors.
Choose English or one of six Celtic languages. The checker uses a separate set of spelling and grammar rules for each language, so it does not treat Celtic writing as English with a different dictionary.
Review a clear suggestion. A likely issue gets an underline and a short explanation. Accept the fix, dismiss it, or leave your text unchanged.
Mac app
The same blas. you use on your phone, built for the Mac. Every lesson, reading, and drill, plus on-device dictation.
Requires macOS 15 or later.
Is it free?
Yes. The first Chrome release is free to install and use.
Does it send my writing anywhere?
No network request is made merely because you type. Passive checks stay local. Linked Premium users can use English-only cloud Deep Review, which is enabled by default and can be turned off in Settings. Deep Review sends only the selected English text and context after you explicitly click; Celtic text is rejected, and Blas does not store raw review text or use it for training. Diagnostic reports send only after you submit; flagged text, sentence context, and page URL stay excluded unless you choose to include them.
Does it work offline?
The core spelling and grammar checker works without a connection. Account sync and dictation need one.
Which dialects does it support?
Irish accepts the standard language plus selected validated Ulster, Connacht, and Munster forms. Dialect and strictness controls let you choose how conservative the checker should be.
Will it replace a tutor or textbook?
No. It's a writing assistant, not a linguistic authority. For anything you publish or submit, cross-reference against teanglann.ie (Irish) or geiriadur.bangor.ac.uk (Welsh), or a published grammar.
Does it work in Google Docs?
Google Docs uses a review-and-copy flow rather than inline underlines. Blas checks the document text and lets you copy a corrected version; it does not write changes back into the document.
Which browsers are supported?
Chrome and Firefox are released. Safari for Mac has a build approved for distribution, which is not the same as a confirmed public listing. The iPad build is still being verified and is not released.
Add the extension to Chrome, choose a language, and keep writing where you already work.
Want the full learning app too? Start with blas.