Mulyadi Subali Indonesian Translator
Post-Editing

Machine Translation Post-Editing (MTPE): What It Is and When to Use It

8 min read
July 2026
Mulyadi Subali
Post-Editing · Agency Resources

Machine translation post-editing gets pitched to project managers as a way to cut cost and turnaround, and in the right situation it does exactly that. In the wrong situation, it produces a document that reads fine on the surface and is quietly wrong in ways that matter — a mistranslated obligation in a contract, a reversed number in a spec sheet, a tone that alienates the audience it was meant for. The difference usually comes down to matching the right level of post-editing to the right content type, which is what I want to walk through here.

What MTPE Actually Is

Machine Translation Post-Editing (MTPE)

The process of a professional human translator reviewing and correcting machine-generated translation output, rather than translating the source text from scratch. The MT engine produces a first draft; the human editor fixes it against the source.

What It Is Not

MTPE is not the same as accepting raw MT output with a quick proofread pass. It is not a way to skip human review — it is a specific, defined editing process with its own quality standards, and a competent post-editor will still catch and fix meaning-level errors, not just typos.

Light Post-Editing vs. Full Post-Editing

Light Post-Editing
The goal is comprehensible, accurate content — not polished prose. I correct mistranslations, factual errors, and anything that would mislead the reader, but I leave awkward-but-clear phrasing alone if fixing it wouldn't change the meaning. Faster and cheaper. Suited to internal documents and high-volume, low-visibility content.
Full Post-Editing
The output needs to read as if it were translated by a human from the start — natural phrasing, correct register, consistent terminology, stylistically appropriate for the audience. This takes closer to the time of a full translation on dense or nuanced source text, but still benefits from MT's head start on repetitive or formulaic sections.

When MTPE Makes Sense — and When It Doesn't

Good fit for MTPE

High-volume internal documentation, product catalogs with repetitive structure, e-commerce listings, user manuals with formulaic phrasing, and any content where turnaround and cost matter more than stylistic polish.

Poor fit for MTPE

Legal and sworn documents, marketing copy that depends on tone and cultural resonance, anything requiring transcreation rather than translation, and content where a single mistranslated clause carries real consequence — contracts, compliance filings, court documents.

Depends on the brief

Financial reports, technical manuals with legal exposure (safety warnings, regulatory language), and internal communications that may later be shared externally. These need a conversation about risk tolerance before defaulting to MTPE.

The MTPE Workflow, Step by Step

1. Source review

Before any MT engine runs, I check the source for anything that will confuse machine translation — ambiguous phrasing, embedded formatting, inconsistent terminology in the original — since MT quality depends heavily on source clarity.

2. MT pass

The source runs through the agreed engine, ideally one trained or customized on the client's domain and, where available, fed by the project's existing translation memory and glossary.

3. Post-editing against the source

I work segment by segment, comparing MT output to the source — not just reading the target for fluency. This catches errors that read smoothly but say the wrong thing, which is the failure mode MT is most prone to.

4. Terminology and consistency pass

A second pass checks that terminology stays consistent across the document, since MT engines can translate the same source term differently depending on surrounding context.

5. Delivery and TM update

The corrected segments feed back into the project's translation memory, so the next MTPE or human-translation pass on similar content starts from a stronger base.

Content Types That Suit MTPE

High-volume document translation
Strong fit for light post-editing where turnaround and cost outweigh the need for polish.
E-commerce and product descriptions
Usually light MTPE, though brand-defining product lines may warrant full post-editing.
Software and website localization
Suited to MTPE for UI strings and help content; marketing pages on the same site often need full post-editing or straight human translation instead.
Internal corporate communications
Frequently a good MTPE candidate, since accuracy matters more than polish and the audience is already internal.
Technical and user documentation
Works well when terminology is controlled and consistent — I saw this directly maintaining the in-house terminology base as Language Lead on the Toyota account, where a controlled glossary made MT output far more reliable to post-edit.
Financial and compliance documents
Requires a case-by-case call — full post-editing at minimum, and for anything with legal exposure, human translation from the start.

What MTPE Can't Fix

MT output can be wrong in ways that don't look wrong.
Machine translation is fluent by design, which means errors often read as confident, grammatically correct sentences that simply say the wrong thing — a negation dropped, a number transposed, a conditional flattened into a statement of fact. A rushed post-edit that only checks for fluency, without comparing every segment back to the source, will miss exactly these errors. This is the main reason MTPE should be scoped and priced as real editorial work, not treated as a light proofread.
Cultural and tonal judgment. MT has no sense of what will land with a specific audience — that requires a human decision, and often a full translation or transcreation approach rather than MTPE.
Ambiguity resolution that depends on context outside the document. A post-editor working only from the visible text can correct grammar and obvious mismatches, but resolving true ambiguity may need a query back to the client.
Legal or regulatory precision. For sworn, certified, or legally binding documents, the standard of accuracy required is not one MTPE — even full post-editing — is built to guarantee.
Scoping an MTPE Project

Light or full post-editing for your Indonesian–English content.

I work from your existing TM and glossary where available, follow ISO 18587-aligned post-editing standards, and flag content types that are a poor fit for MTPE before starting rather than after. Send documents for a quote and I'll recommend light, full, or straight human translation based on what the content actually needs.

Post-Editing / MTPE Service Details →

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