Head to head · Translation · October 2026 research run

Localazy vs SYSTRAN Translate API

Localazy scores 54.4 (C) on agent readiness against SYSTRAN Translate API's 40.2 (E), and leads in 5 of 7 scored categories. SYSTRAN Translate API leads on security & auth and payments & pricing. Both do translation.

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

Which one, for what

Localazy C

Best for App and game teams that keep source strings in a TMS and want agents to push keys, pull translations or run AI translation with a glossary.

Ahead on

  • Reliability, 68 against 25
  • Schema & documentation, 51 against 42
  • Agent ergonomics, 62 against 54
  • Maintenance & community, 75 against 4

Watch for

No OpenAPI spec, and llms.txt only lists top-level pages

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 37
  • Payments & pricing, 40 against 35

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

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

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.

Maintenance & community Localazy +71

Localazy 75

@localazy/api-client 2.3.2 on 26 October 2026 (30). Releases 2.3.0 (12 August), 2.3.1 (29 September) and 2.3.2 (26 October) in the last 90 days (20). Support by email, blog release updates, and public GitHub repositories, but we didn't read issue reply times (7). The TypeScript client and the CLI (2.0.12 on 31 July 2026) are current (13). The client repository shows coverage badges; we didn't confirm CI runs (5). 30+20+7+13+5 = 75.

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.

Reliability Localazy +43

Localazy 68

Hosted lines, for the REST API at api.localazy.com. Better Stack status page with Web, API, Public API, Payments and Connect API components and 30, 60 and 90-day uptime (20). The incidents page reports none for September, October or November 2026, but the Public API shows 99.805% uptime in one 30-day bucket, roughly an hour and a half of downtime with no incident posted, so the line is held below clean (25). Limits per plan of 100 requests a minute and 10 a second, plus daily import and fetch caps per project (15). No 429 or retry guidance found in the API docs (0). No SLA found on the pricing page or in the terms (0). The core API is GA; the AI Translation endpoint is marked beta (8). 20+25+15+0+0+8 = 68.

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.

Security & auth SYSTRAN Translate API +18

Localazy 37

Bearer tokens in the Authorization header. A project token reaches every endpoint of one project with read and write access; a translation token reaches only the AI Translation endpoint; organisation tokens are in beta on request (20). The translation token is the only least-privilege option, and project tokens can delete keys and glossary items without a confirmation step (10). The API returns strings written by translators and contributors, with no guidance on untrusted content (5). No per-call log or audit trail for tokens found (2). localazy.com/.well-known/security.txt and /security return 404, and we found no disclosure policy or certification (0). 20+10+5+2+0 = 37.

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.

Schema & documentation Localazy +9

Localazy 51

No OpenAPI or other machine-readable contract was found (0). localazy.com/llms.txt is a six-link index of top-level pages, with no Markdown docs for agents (5). Each endpoint page states which token types can call it, whether write permission is needed and the minimum role, and the limits page says to use the CDN, not the API, for production fetches (14). Request bodies list required and optional fields with limits, such as 512 characters for a key and 1,000 for a comment (12). Sample requests, responses and error responses per endpoint (13). Docs pages carry 'last updated' dates and the blog posts dated release updates, but there's no API version or changelog (7). 0+5+14+12+13+7 = 51.

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.

Agent ergonomics Localazy +8

Localazy 62

API reading. List endpoints return whole projects, files and keys with few output controls (13). Filtering by file, language and tags, and batch imports of up to 1,000 keys and 50 files a request (14). Error responses are documented per endpoint, with HTTP codes and messages (12). No idempotency keys, and the docs warn against parallel imports into the same new file (8). Official TypeScript API client, a CLI and Android and iOS libraries, with few required fields (15). 13+14+12+8+15 = 62.

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.

Payments & pricing SYSTRAN Translate API +5

Localazy 35

No x402, MPP or L402 (0). Plan prices are public ($34, $78 and $175 a month billed annually) and credits are $1 each, with Localazy AI at about $0.005 a word on average, so partial per-unit credit (15). A free plan for small projects and a 14-day Business trial with no credit card (20). A person signs up in a browser and mints tokens in the developer settings (0). 0+15+20+0 = 35.

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.

Score by category

CategoryWeight this runLocalazySYSTRAN Translate APIEdge
Reliability16%206825Localazy +43
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25142Localazy +9
Agent ergonomics13%16.26254Localazy +8
Security & auth14%17.53755SYSTRAN Translate API +18
Payments & pricing10%12.53540SYSTRAN Translate API +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8754Localazy +71
Transparency & trust7%8.85753Localazy +4
Negative events≤1500
TotalC 54.4/100E 40.2/100

Facts side by side

FactLocalazySYSTRAN Translate API
KindHTTP APIHTTP API
VendorLocalazy s.r.o.SYSTRAN (ChapsVision)
Hosted endpointno (local only)https://api-translate.systran.net
TransportsHTTPHTTP
AuthTokenOAuth or key
PricingFreemiumPay per use
x402nono
LicencenoneProprietary service under the SYSTRAN Translate PRO terms and conditions
Read-only variant documentednono
llms.txtyesno
Last release2026-10-262023-06-16
Terms last updatedno date givenno date given
Privacy policy last updatedno date givenno document linked
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessnot found in the textyes
Terms restrict benchmarkingnot found in the textyes
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
Popularity61k npm/wknone
Agent reviewsnone2.8/5 (4)

How the scores have moved

Verdicts

Localazy

Localazy is a localisation platform whose REST API, CLI and AI Translation endpoint use project-scoped bearer tokens, with published limits, a free plan and a no-card trial. There's no OpenAPI spec, no 429 guidance, no security.txt or disclosure policy, and project tokens carry full read and write access.

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.

Before you call either

Localazy

  1. Ask for a translation token when the task is only machine translation, rather than a project token
  2. Keep under 10 requests a second and the plan's daily import and fetch caps per project
  3. Use the Localazy CDN, not the API, to fetch translations in a live app
  4. Import at most 1,000 keys and 50 files a request, and don't run parallel imports into the same new file
  5. Check the account's credit balance before bulk AI translation, since each word uses credits

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

Questions

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

Localazy scores 54.4 (C) on agent readiness against SYSTRAN Translate API's 40.2 (E), and leads in 5 of 7 scored categories. SYSTRAN Translate API leads on security & auth and payments & pricing.

Do Localazy and SYSTRAN Translate API need an API key?

Localazy needs an access token. SYSTRAN Translate API takes an API key or an OAuth sign-in.

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

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

Other comparisons with Localazy or SYSTRAN Translate API

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