Transept AI is a translation workspace that keeps a memory of your terminology, tone, and past editing decisions, then applies them automatically to new documents. Instead of translating each file cold, you build a glossary and styleguide once and Transept enforces both every time you translate afterward.
Short answer: Transept AI is an AI translation workspace that pairs document translation with reusable glossaries, styleguides, and translation memory. The Free plan gives 1,500 words a month with no credit card; Starter runs €29/month for 100,000 words with Pro mode and unlimited AI assistant messages. It imports DOCX, PDF, Markdown, and TXT files.
When I checked Transept's sign-up flow, its pricing page, and its help documentation, I wanted to see what you actually get before committing a card. This guide covers what you need before you start, the setup steps, prompts worth copying for its Literess assistant, and the mistakes that waste a plan's word allowance fastest based on how the pricing and word-cost math actually works.
What you'll need
You need a document to translate — DOCX, PDF, Markdown, or TXT — or content pasted directly into the editor. No credit card is required for the Free plan, which caps you at 1,500 words a month. If you're translating for a client or a specific brand voice, gather your preferred terminology (product names, do-not-translate terms) and any style notes before you start; Transept's glossary and styleguide features only help once you've actually filled them in. Teams should also decide who owns the shared glossary, since Starter and Pro plans let you invite collaborators who'll see and edit the same term list.
Step-by-step: Setting up Transept AI
1. Create a free account
Sign up at transept.ai with no card required. The Free tier includes translation memory, glossary, styleguide, QA checks, and import/export on every plan — Transept doesn't gate those features behind Starter, it gates word volume instead.
2. Import or paste your content
Upload a DOCX, PDF, Markdown, or TXT file, pull a page from Notion or Google Drive, or paste raw text directly into the editor. Transept's help center specifies that formatting carries through import and export for DOCX and Google Docs files, which matters if you're translating anything with headers or tables you don't want to rebuild by hand.
3. Pick a translation mode
Transept offers three speeds: Fast, Standard, and Pro. Standard mode costs one word of your allowance per source word; Pro mode, which uses a more capable model for tone and nuance, costs three words per source word. That 3x multiplier is easy to miss and it's the single biggest reason a Free-plan test run burns through 1,500 words faster than expected.
4. Build a glossary and styleguide
Add brand names, jargon, and terms that should never be translated, plus notes on tone (formal, casual, technical). Transept enforces glossary terms on every text block it translates afterward, and you can build the list either manually or from an existing document.
5. Review with Smart Proofread
Run Smart Proofread before you export. It flags terminology drift and glossary violations against the terms you've defined — but only against terms you've actually defined, so this step is only as useful as the glossary you built in step 4.
6. Export to your target format
Send the finished translation to Word, Markdown, Notion, or Google Docs, with original formatting preserved for files that came in as DOCX or Google Docs. Translation memory rebuilds in the background automatically and doesn't cost you any of your word allowance — only new text you haven't translated before does.
Example prompts you can copy
Transept's Literess assistant is conversational, so specific instructions get better results than generic ones. A few to adapt:
- "Translate this into Spanish for a Mexican audience, formal register, and flag any phrase where a literal translation would sound stiff."
- "Build a glossary from this document — pull out every brand name and product term, and mark them do-not-translate."
- "This paragraph reads too casual for our styleguide. Regenerate it in a more formal tone without changing the meaning."
- "Check this translation against our glossary and list every term that doesn't match."
Vague prompts like "make it sound better" give Literess nothing to act on. Naming the audience, register, and what specifically should change gets a usable result on the first pass.
Common mistakes to avoid
The mistake I'd flag first, based on Transept's own word-cost math: switching straight to Pro mode without checking the multiplier first. At three words of allowance per source word, a single mid-length document in Pro mode can burn through most of the Free plan's 1,500-word cap, leaving nothing for a second document that same month. Second, skipping the glossary step and translating a full document cold — Smart Proofread only catches drift against terms you've actually defined, so an empty glossary means it has nothing to check against. Third, assuming unused monthly words roll over; they don't, and a lightly used Free or Starter month resets to the base allowance on the next billing cycle. Fourth, forgetting that top-up word packs never expire but monthly plan words do, so it's worth using your monthly allowance before it resets rather than saving it. Fifth, not proofreading Pro-mode output just because it costs more — a higher-cost mode changes which model does the work, not whether you should still read the result before sending it out.
Transept AI plans at a glance
| Free | Starter | Pro | |
|---|---|---|---|
| Price | €0/month | €29/month | €79/month |
| Words/month | 1,500 | 100,000 | 300,000 |
| Pro mode (3x model) | No | Yes | Yes |
| Literess assistant | 10 messages (lifetime) | Unlimited | Unlimited |
| Team seats | — | €29/seat (100k words each) | Included tier pricing |
| Top-up packs | Available | Available | Available |
| Credit card required | No | Yes | Yes |
Top-up packs run €19 for 50,000 words, €69 for 200,000 words, and €149 for 500,000 words, and don't expire — useful if you have one large project rather than a steady monthly volume. Figures confirmed on Transept’s pricing page on August 19, 2026; check the live page before budgeting, since SaaS pricing changes without much notice.
Tools that make this easier
If translation is one piece of a broader content workflow, my best AI writing tools guide covers where a tool like Transept fits next to drafting and editing software. Teams evaluating whether a specialized €29/month tool is worth adding to their stack should also look at best AI tool for small business, which compares broader-scope options at similar price points. Since Transept lets you choose which underlying model handles Standard versus Pro mode, best AI models is a useful primer on what actually changes between a fast, cheap model and a slower, more capable one. If you're localizing marketing or product copy rather than straight documents, best AI tool for content creation covers the drafting side before translation. And for the English-language writing quality that determines how well any translation holds up, my Jasper review covers a dedicated copywriting tool worth pairing with a translation workspace like this one.
My take
Transept's actual differentiator is narrower than the marketing copy suggests, but it's a real one: most translation tools give you a glossary lookup, while Transept keeps memory of the editing decisions behind that glossary and reapplies them without you re-explaining tone every time. The Free plan's 1,500 words is genuinely enough to test the workflow, not just the interface, and the fact that translation memory rebuilding never costs word credits means you're not penalized for reusing your own past work. Where I'd slow down before paying: the Pro-mode 3x word multiplier makes the jump from Free to Starter's 100,000 words shrink fast if you lean on the higher-quality model, and at €79/month, Pro competes with dedicated CAT tools that have a longer track record with professional translators. For a solo user or small team translating documents with consistent terminology, Starter is the plan to actually test against your own content before committing further.
Frequently Asked Questions
Is Transept AI free?
Yes, with limits. The Free plan gives 1,500 words a month with no credit card required, plus full access to glossary, styleguide, QA, and translation memory. Paid plans start at €29/month for 100,000 words and Pro mode.
How long does it take to set up Transept AI?
Account creation and your first translation take a few minutes — Transept's own help center describes a first translation as a two-minute, start-to-finish process. Building a useful glossary and styleguide takes longer if you want Smart Proofread to actually catch drift, since it only checks terms you've defined.
What is the easiest way to use Transept AI?
Start in Standard mode with a short document, build your glossary from that same document, then run Smart Proofread before you export. Switching to Pro mode only after you've confirmed the workflow fits avoids burning through your word allowance on the 3x multiplier before you know if the tool is right for your content.
Does Transept AI support file formats other than plain text?
Yes. It imports DOCX, PDF, Markdown, and TXT files, plus pages from Notion and Google Drive, and exports to Word, Markdown, Notion, or Google Docs with original formatting preserved for documents that came in as DOCX or Google Docs.
How is Transept AI different from a standard machine translation tool?
Standard translation tools generally treat each document as a fresh job. Transept's translation memory and decision-context memory carry glossary terms, tone choices, and past edits forward automatically, so a second document in the same project doesn't require re-explaining your styleguide.