Smartcat reads all three Japanese scripts in one pass, holds one consistent English register across a keigo-heavy document, and rebuilds the PDF so tables, images and formatting survive the trip into English.
Horizontally set Japanese only — vertical (tategaki) typesetting is not supported. Scanned, image-of-text pages take a separate route you select at upload.
1,000+ enterprise brands trust Smartcat for Japanese to English PDF workflows.
A single Japanese sentence mixes kanji, hiragana and katakana with no spaces between words, so any tool that splits text on whitespace shreds it before translation starts.
Furigana readings printed above kanji get scooped into the extraction as stray syllables.
Scanned contracts carry hanko seals stamped over the text that matters most.
Formal documents are often set vertically (tategaki) — a case no automated pipeline here handles, ours included.
Then the translation itself runs 20–60% longer in English than the Japanese it replaces, so in a fixed layout it overprints, truncates or vanishes unless the document is actually rebuilt.
Smartcat handles this at the platform level. Kanji, hiragana and katakana are treated as one language, not three alphabets, and text is segmented linguistically before translation — which is what keeps a sentence whole when the source has no word boundaries.
Keigo is handled with custom prompts, AI translation profiles and your glossary, so one English register holds across a document set instead of drifting. The PDF is then rebuilt rather than patched, with text boxes, tables and columns reflowing to absorb English that runs 20–60% longer.
One limit worth knowing up front: vertical (tategaki) typesetting is not supported — re-export the original horizontally, or hire a Japanese–English translator from the Marketplace. Comparing approaches rather than translating a file today? Start with our guide to document translation.
100 MB
maximum PDF size in the AI workflow
No page limit — a typical 10–20 page document runs 15 to 45 minutes, and 60+ pages takes significantly longer.
20–60%
longer in English than in Japanese
The layout engine reflows text boxes, tables and columns during the rebuild so the expansion is absorbed instead of overflowing.
3 scripts
read together in one pass
Kanji, hiragana and katakana are segmented linguistically, since written Japanese has no spaces between words.
Smartcat handles high-volume pairs and long-tail requests from the same workspace.
High volume customer and marketing content
Brand, legal, and support documents
Every source language we support, in one place
Supplier, quality, and compliance content
Technical, legal, and compliance documents
Smartcat is SOC 2 Type II compliant — encryption in transit and at rest, isolated workspaces and role-based access.
Pricing is metered in Smartwords, so you pay for word count rather than pages, and the first 15 days are free with 15,000 Smartwords and no credit card.
for ease of setup, on G2
for ease of use, on G2
enterprise brands
encryption in transit and at rest, isolated workspaces, role-based access
Immigration offices, courts and universities usually require certified human translation, where the linguist signs the translation and Smartcat facilitates it.
Use Smartcat for the fast working version and route the official one to a professional — or book a demo to ask about review options.
Smartcat's Japanese-to-English PDF translator extracts the text from a Japanese PDF, translates it into English, and rebuilds the document with the original layout preserved.
Scanned, image-of-text pages are handled on a separate documented route: you select the pdfimageonly parsing method at upload and each page runs through the image-translation pipeline, which is also the only route that supports handwritten content.
Any file can be routed through a professional Japanese-English reviewer before the finished PDF is exported.
From upload to export
One workflow, five stages, one workspace.
1
Upload the Japanese PDF
Up to 100 MB, any page count. Horizontally set Japanese; if the document is set vertically, stop here and use the human route. For scanned pages, choose pdfimageonly as the parsing method — it is not detected for you.
2
Confirm the pair
Japanese to English; add more target languages if you need them.
3
Get the English draft
Glossary and translation memory are applied, so katakana loanwords and spec terms render consistently.
4
Review where it matters
Check the draft against the live layout, and add a professional reviewer for contracts and filings.
5
Export the finished PDF
Same structure, in English.
Upload the file, review the draft, export a finished document — three scripts read together, register held, layout rebuilt. Free for 15 days with 15,000 Smartwords, no credit card.
Technical specs and manuals, keigo-heavy business correspondence, training materials and stamped back-office scans — the files where script, register and layout carry the meaning.
Immigration offices, courts and universities usually require certified human translation, where the linguist signs the translation and Smartcat facilitates it.
Each authority sets its own certificate, registration and legalization requirements, so confirm those first — and book a demo if you want help matching a translator to your deadline.
Every translation lands in a complete visual editor. Click any element — a keigo phrase that lands too formally in English, a spec heading that needs different wording — and say what you want in plain language, then see the change before you accept it. No designer round-trips, no re-running the job.
| What you get back | ✓ A finished English PDF that still looks like the Japanese original | ~ A rough file or copyable text | ~ Translated text in a chat window that you rebuild into a document yourself |
| Japanese layout and all three scripts preserved on export | ✓ Yes — kanji, hiragana and katakana read together in one pass, with boxes, tables and columns reflowed for 20–60% longer English (horizontal typesetting only) | ~ Partial — formatting often lost, and furigana get scooped into the text as stray syllables | ✗ No — it returns text, not your rebuilt Japanese file |
| Scanned / image-only Japanese PDFs | ✓ Yes — select the pdfimageonly parsing method at upload; it is also the only route that supports handwritten content | ~ Limited | ~ Reads many scans, but the output is still text |
| Long Japanese documents in one pass | ✓ AI PDF workflow takes files up to 100 MB with no page limit; 10–20 pages in 15–45 minutes | ~ Per-file size and page caps | ~ Chat context limits — long Japanese documents get truncated or chunked |
| One consistent English register across a document set | ✓ Custom prompts, AI translation profiles and your glossary pin the register — set once, held across the set | ✗ No | ~ You can describe the tone in each prompt; nothing is stored as a reusable profile |
| Japanese–English human review in the same workflow | ✓ Marketplace Japanese–English linguists reviewing against the live layout | ✗ No | ✗ No — you arrange review yourself |
| Run the same job again next month | ✓ Projects, Chat and version history — resume and re-export | ✗ Manual every time | ~ Re-prompting works, but output varies run to run |
Topcon, the Tokyo-headquartered positioning and optics manufacturer, delivered 298 localization projects in two years across 11 languages and 29 countries, cutting production of one eLearning course in 10 languages from 13 hours to 11 hours, with a further two hours or so saved per course through automated project management.
“We have produced 298 projects; of these, over 80% were for eLearning courses. Smartcat allowed us to increase our initial two target languages to ten easily and quickly,” says Michelle Quirke, Program Engagement Manager at Topcon.
Kids2 cut ecommerce content turnaround by 92% — from 90 minutes to under 5 minutes per Salsify upload — using the Smartcat–Salsify connector.
10 days to 2–3
faster turnaround per project
Smith+Nephew cut translation delivery from ten days to two or three days with Smartcat.
Up to 70%
lower translation cost
Stanley Black & Decker cut costs while increasing output and improving quality.
31 hours
saved monthly
Babbel saved time across marketing and learning teams.
Three scripts read together, register held across the document set, layout rebuilt on export. Free for 15 days with 15,000 Smartwords, no credit card.
A typical 10–20 page document runs 15 to 45 minutes. There is no page limit, but 60+ pages takes significantly longer, and the 100 MB file ceiling applies to the AI PDF workflow.
No — vertical (tategaki) typesetting is not supported today. Rotate to a horizontal source where you can, or route vertically set documents to a human translator — you can hire a Japanese-English one from the Marketplace inside the same project.
Yes — they're one language, and Smartcat segments and translates them as such. Katakana loanwords and product names are kept consistent through the glossary rather than re-guessed on every page.
Yes, with one routing step: image-only PDFs aren't handled by the AI PDF workflow, so at upload you choose pdfimageonly as the parsing method and each page runs through the image-translation pipeline.
Printed text works well; hanko seals are preserved as images, so text underneath a stamp isn't reliably readable, and handwriting should go to human transcription.
English typically runs 20–60% longer than Japanese. The rebuild reflows text boxes and table cells to absorb the expansion; very tight fixed layouts deserve a quick visual check before export.
Free for 15 days with 15,000 Smartwords and no credit card — full access to translation capabilities — then paid. There is no permanently free tier.
Free tools are fine for a disposable file; this is for documents where scripts, layout and terminology have to survive.
Handwritten Japanese — even neat forms — and low-resolution scans defeat OCR, and a misread kanji produces a fluent but wrong English sentence. For those files, put a human reviewer on the sections that carry risk, or start with professional transcription.
Smartcat is SOC 2 Type II compliant, with encryption in transit and at rest, isolated workspaces and role-based access. Details on the security page.
Book a demo — a 1:1 consultation with a Smartcat specialist, no commitment and no form queue.