Transcripts, certificates and notarial records — translated with the table structure intact, every digit conserved and machine-checked, every term rendered the same way throughout, and the source and translation matched item by item. Anything unaccounted for stops the job for human review; nothing passes silently.
PDF / PNG / JPG · Chinese ⇄ English · artifacts deleted after 30 days
English course names run two to three times longer than the Chinese, yet every row stays a row and every column stays a column — the reader finds any item on both sides by its place in the table. Every screenshot here is real pipeline output; the documents are synthetic fixtures — a real customer document never becomes marketing material.
Before translation, code freezes every critical value — grades, credits, IDs, dates, amounts — into immutable tokens the model cannot touch; afterwards code verifies each one back into place, and a conservation gate compares the full set of digits on both sides. The model never gets a chance to re-type your GPA.
Certified translation has one hard rule: stamps, embossed seals, seam seals and signatures are described in brackets and never pasted in as images — copying the red seal across is a leading reason documents get rejected. CertTwin reads the text inside the seal, translates it, writes a proper italic bracketed note, and makes you approve each one.
Click any text on the page and the matching place highlights on the source and the translation at once, so you never hunt for correspondences. Edits redraw immediately, seal descriptions need your explicit approval, and every action lands in an audit log.
Zero silent loss is a checkable property, not a slogan: extraction is reconciled against the document's own text layer, anything the model missed is recovered from it, repeated terms must translate identically everywhere, and every draft runs all nine checks. If any one fails — including two models reading the same scanned digit differently — the job stops for human review instead of going out.
| Coverage | Every page extracted, native text layer fully reconciled | pass |
| Visual elements | Seal and signature descriptions await your approval | review |
| Number conservation | The set of digits matches between source and translation | pass |
| Block completeness | No semantic block dropped or blocked | pass |
| Language purity | No source-language residue or Chinese punctuation left behind | pass |
| Term consistency | A repeated source string translates identically everywhere | pass |
| Minimum font size | Nothing squeezed below the readable floor | pass |
| Layout collisions | Glyph-level scan; any overlapping text is held | pass |
| Side-by-side review | Human sign-off — never auto-approved | review |
Translation agencies, law firms and admissions services process documents by the folder, not one at a time. The pipeline behind CertTwin is queue-based and runs pages in parallel — and every document in a batch passes the same nine gates individually, so scale never dilutes scrutiny. Batch intake is in invited testing: if you process volumes, write to us and we will set you up.
A PDF, a scan or a phone photo. Files go straight to private storage, with no third-party middleman.
IDs, dates and amounts are frozen before translation and verified back afterwards. On scans, a second model re-reads the digits.
Check each place, edit in line, approve the seal descriptions, and export the review draft as a PREVIEW_ONLY PDF.
Tuned for the formatted paperwork behind study abroad, immigration, visas and notarization.
No. Every page is stamped PREVIEW_ONLY — a review draft meant for human verification and whatever certification step follows. It is not itself a certified translation and does not guarantee acceptance by any authority. Whether a translator's declaration gets attached is your call.
They are used only to produce your translation, processed by Google Cloud (Vertex AI) in the United States, and the artifacts are deleted after 30 days. This site sells nothing and never asks for passwords, card numbers or ID numbers.
Chinese ⇄ English today — the pair behind most study-abroad and immigration paperwork. More are on the roadmap.
The product is in closed testing, and we want every problem a real document exposes to actually get fixed. Email us with your document types and purpose to join.
Free during closed testing. Send us an email describing what you need translated and we will open an account.