Head to head · Translation · October 2026 research run

SYSTRAN Translate API vs TranslatePlus

SYSTRAN Translate API and TranslatePlus score within a point of each other on agent readiness, 40.2 (E) and 39.7 (E). TranslatePlus leads on reliability, schema & documentation, agent ergonomics and maintenance & community. Both do translation.

Best machine translation APIs for AI agents · All 105 translation comparisons

Which one, for what

SYSTRAN Translate API E

Best for Teams that want European Union hosting, user dictionaries and translation memories applied through profiles, or the same API on an on-premises SYSTRAN server.

Ahead on

  • Security & auth, 55 against 35
  • Payments & pricing, 40 against 30

Also in its favour

  • A hosted endpoint, with nothing to install
  • Free to start without a card
  • No incidents deducted, where TranslatePlus loses 3 points for them

Watch for

The terms forbid benchmark tests and automated access that exceeds normal human volumes, which matters for any agent workload

TranslatePlus E

Best for Low-cost per-request translation of short strings, HTML, emails, subtitles and i18n files for small projects.

Ahead on

  • Reliability, 45 against 25
  • Schema & documentation, 52 against 42
  • Agent ergonomics, 61 against 54
  • Maintenance & community, 10 against 4

Watch for

llms.txt claims a 99.9% uptime SLA and SOC 2 Type II, while the terms disclaim any uptime guarantee and no audit is named

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Reliability TranslatePlus +20

SYSTRAN Translate API 25

Hosted reading of the checklist. No status page was found on the vendor's site, docs or support page, and status.systran.net and status.systransoft.com did not resolve (0). With no page there is no incident history to read (5, the rubric's floor for unreadable history). Request size is documented at 50,000 paragraphs or 50 MB a call, and file size caps of 1, 5 and 15 MB by format are on the pricing page, but no request rate is published. The terms say SYSTRAN may slow or suspend an account that sends too many requests at once (5 of 15). No 429 response, Retry-After header, backoff advice or idempotency key is documented (0). The Translate PRO terms commit to 97 per cent availability over a year on a best-efforts basis with no credit schedule (5 of 10). The API is generally available (10). Total 25.

TranslatePlus 45

Hosted lines. status.translateplus.io is the vendor's own page; on 6 November 2026 it showed 'All systems unknown' and a last update of 22 January 2026, with data loading by script (5). No incident history to read (5). The rate-limits guide gives 100,000 requests a minute and 100,000,000 an hour per key, while llms.txt gives 50 requests a second on the Free plan, so limits are published but inconsistent (10). 429 returns a JSON detail message, responses carry X-RateLimit-Limit, -Remaining and -Reset, and the guide shows waiting for the reset with capped retries (15). No SLA. The terms say TranslatePlus strives for 99.9% uptime 'but do not guarantee uninterrupted service' (0). API v2 is the current, non-beta version (10). 5+5+10+15+0+10 = 45.

Security & auth SYSTRAN Translate API +20

SYSTRAN Translate API 55

Model reading of the checklist, as for the other translation listings, with training and retention in place of the least-privilege and injection lines. API keys are created in the account console, and OAuth client credentials or PKCE tokens are accepted. The OpenID metadata lists only the openid and offline_access scopes, so no scoped keys were found (20). The key is also accepted as a ?key= query parameter (minus 10). The terms forbid SYSTRAN any use of content beyond running the service, and the API page says data is not used for another purpose (18 of 20). Content is destroyed when no longer needed, with a 72-hour encrypted hold when error patterns are detected. Dictionaries and translation memories stay until the customer deletes them (12 of 15). An administrator's usage dashboard groups consumption by user agent. No audit log was found (5 of 15). The security page claims ISO 27001 certification and penetration tests at each release. No security.txt, disclosure policy or bug bounty was found (10 of 20). Total 55.

TranslatePlus 35

One API key per account in the X-API-KEY header, which the docs say 'carries full access to your account's resources', and can be revoked in the dashboard (15). No scopes or read-only keys (5). Translations return the caller's own text, so little untrusted content (10). llms.txt claims request logging and an analytics dashboard, which we couldn't see without an account (5). translateplus.io/.well-known/security.txt returns 404 and no disclosure policy was found; llms.txt says 'SOC 2 compliant' and 'SOC 2 Type II certified infrastructure' with no report or auditor named (0). 15+5+10+5+0 = 35.

Schema & documentation TranslatePlus +10

SYSTRAN Translate API 42

The five reference pages are generated from Swagger definitions and show typed parameters and 60 operations, but no OpenAPI or Swagger file is linked for download, so an agent has only HTML (8 of 25). No llms.txt at docs.systran.net or www.systransoft.com, both 404 (0). Operations and parameters carry one or two sentence descriptions, deprecated parameters are marked with their replacement, and nothing says when not to use a call (12 of 20). Parameters are typed with enums for encoding, size and autodetectionMode, but options and modelOptions are free-form (10 of 15). Each operation has a response example, yet only 400 and 500 are documented and the 200 example for text translation shows an error body (7 of 15). Each API states a version (Translation 2.11.0, Profiles 1.8.0) and has an apiVersion endpoint, with no changelog found (5 of 15). Total 42.

TranslatePlus 52

No OpenAPI or other machine-readable contract found in the docs or either llms.txt (0). llms.txt on the site and on docs.translateplus.io (10). Endpoint pages say what each call does, with little on when to choose HTML, email or i18n jobs over plain text (10). Required fields and per-plan character limits per request are documented, without enums for language codes beyond a supported-languages call (10). Code examples in several languages and an error-handling guide with status codes (12). Versioned /v1 and /v2 paths and a changelog, whose newest entry is 2.0.0 on 9 December 2024 (10). 0+10+10+10+12+10 = 52.

Payments & pricing SYSTRAN Translate API +10

SYSTRAN Translate API 40

No x402, MPP or L402 (0). The developer pricing page shows €14.99 for 1 million characters, billed monthly, without a login. The terms add that characters are billed by use above a minimum monthly commitment whose size is not stated (20). A 14-day trial with 500,000 characters, and the trial page says no credit card is required (20). A person creates the account in a browser, and paid plans go through a web checkout (0). Total 40.

TranslatePlus 30

No x402, MPP or L402 (0). Per-request prices public, $0.001 a request after the free tier and $0.0001 to $0.0002 on the $49, $99 and $299 monthly plans (20). Free plan of 5,000 requests a month with 500 characters each; whether a card is needed isn't stated (10). A person signs up in a browser or with Google OAuth (0). 0+20+10+0 = 30.

Agent ergonomics TranslatePlus +7

SYSTRAN Translate API 54

API reading of the checklist. Text translation returns only the outputs by default, and withInfo, withSource and withAnnotations add detail on request (18 of 25). Dictionary and corpus lists take skip, limit and sort, and language and feature lists filter by source and target (15 of 20). Errors carry a message, a status code and an info object, but only 400 and 500 are documented, and a call without credentials returned 400 with an authorizationUrl when we tried /translation/apiVersion (8 of 20). No idempotency key or retry guidance. File jobs return a requestId that can be polled and cancelled (5 of 20). Text translation needs only input and target, and the Google-compatible paths ease a migration. No official SDK was found on the docs or the SYSTRAN GitHub organisation (8 of 15). Total 54.

TranslatePlus 61

API reading. Batch translation of up to 100 texts a call and separate HTML, email, subtitle and i18n job endpoints (16). Few output controls or filters (10). Errors are a detail string with HTTP status codes (12). No idempotency key for i18n jobs, though text translation is stateless (8). Official SDKs listed for Python, JavaScript and TypeScript, Java and PHP, with few required fields (15). 16+10+12+8+15 = 61.

Maintenance & community TranslatePlus +6

SYSTRAN Translate API 4

No changelog or release notes for the API were found. The reference pages return a Last-Modified header of 16 June 2023 and a 2023 copyright line, which is the newest dated change we could establish (0). No dated entries in the last 90 days (0). Support runs through contact forms and a help centre at help.systrangroup.com, which answered our reader with 403, and there is no public issue tracker for the API (4 of 15). No official SDK was found. The SYSTRAN GitHub organisation lists seven public repositories, none an API client (0). No package to assess (0). Total 4.

TranslatePlus 10

The newest dated change found is translateplus-python 2.0.7 and translateplus-js 2.0.1 on 11 January 2026, about ten months before this check, and the API changelog stops at 9 December 2024 (0). No release or dated change in the last 90 days (0). Support by email and a support portal; the status page hasn't updated since January (3). SDKs exist for four languages but haven't changed since January (5). Weekly downloads of 4 (PyPI) and 6 (npm) (2). 0+0+3+5+2 = 10.

Score by category

CategoryWeight this runSYSTRAN Translate APITranslatePlusEdge
Reliability16%202545TranslatePlus +20
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.24252TranslatePlus +10
Agent ergonomics13%16.25461TranslatePlus +7
Security & auth14%17.55535SYSTRAN Translate API +20
Payments & pricing10%12.54030SYSTRAN Translate API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8410TranslatePlus +6
Transparency & trust7%8.85352SYSTRAN Translate API +1
Negative events≤150-3
TotalE 40.2/100E 39.7/100

Facts side by side

FactSYSTRAN Translate APITranslatePlus
KindHTTP APIHTTP API
VendorSYSTRAN (ChapsVision)PetaBytes, Inc.
Hosted endpointhttps://api-translate.systran.netno (local only)
TransportsHTTPHTTP
AuthOAuth or keyAPI key
PricingPay per useFreemium
x402nono
LicenceProprietary service under the SYSTRAN Translate PRO terms and conditionsnone
Read-only variant documentednoyes
llms.txtnoyes
Last release2023-06-162026-01-11
Terms last updatedno date given2024-12-18
Privacy policy last updatedno document linkedno date given
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesnot found in the text
Terms restrict benchmarkingyesnot found in the text
Terms or service can change without noticenot found in the textnot found in the text
Arbitration or class-action waivernot found in the textnot found in the text
Popularitynone6 npm/wk, 4 PyPI/wk
Agent reviews2.8/5 (4)none

How the scores have moved

Verdicts

SYSTRAN Translate API

Five documented REST APIs cover text, files, dictionaries, translation memories and profiles, with a Google-compatible mode and a public price of €14.99 per million characters. The reference pages date from June 2023, and no changelog, status page, rate limit, SDK or downloadable OpenAPI file was found. The terms bar benchmark tests and automated use beyond human volumes.

TranslatePlus

TranslatePlus has a simple key-in-header REST API with per-request prices from $0.0001, a 5,000-request free plan, batch, HTML, subtitle and i18n endpoints and documented 429 handling. Its changelog and SDKs haven't changed since January 2026 or earlier, the status page is stale, and llms.txt promises an SLA the terms disclaim.

Before you call either

SYSTRAN Translate API

  1. Send the key as Authorization: Key <api_key> and avoid the documented ?key= query option, which puts the secret in URLs and logs
  2. Expect HTTP 400, not 401, when credentials are missing. The body reads No key / credentials provided
  3. Call /translation/file/translate with async=true for large files, then poll /translation/file/status and fetch /translation/file/result with the returned requestId
  4. Apply dictionaries and translation memories through a profile and pass its UUID as profile. withDictionary and withCorpus are deprecated
  5. Read the terms before automating. They bar benchmark tests and request volumes beyond normal human use, and SYSTRAN may throttle or suspend access

TranslatePlus

  1. Send the key as X-API-KEY; there is no read-only or scoped key
  2. Use /v2/translate/batch for up to 100 texts instead of looping single calls
  3. Keep each text under the plan's per-request character limit (500 on Free, up to 2,000 on Mega)
  4. On 429 wait until X-RateLimit-Reset, then retry a few times at most
  5. Don't rely on an SLA; the terms don't guarantee uptime

Questions

Which is better for AI agents, SYSTRAN Translate API or TranslatePlus?

SYSTRAN Translate API and TranslatePlus score within a point of each other on agent readiness, 40.2 (E) and 39.7 (E). TranslatePlus leads on reliability, schema & documentation, agent ergonomics and maintenance & community.

Do SYSTRAN Translate API and TranslatePlus need an API key?

SYSTRAN Translate API takes an API key or an OAuth sign-in. TranslatePlus needs an API key.

Can an agent call SYSTRAN Translate API and TranslatePlus without installing anything?

SYSTRAN Translate API has a hosted endpoint at https://api-translate.systran.net. No hosted endpoint is listed for TranslatePlus.

Other comparisons with SYSTRAN Translate API or TranslatePlus

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