Frenet
Cheap Correios and carrier quotes that most Brazilian merchants like, but past outages hit checkout, support is email-only for many, and multi-box orders and per-product dimensions are weak.
Should you install it?
Frenet is a reasonable choice for a Brazilian Shopify store that wants cheap Correios and transportadora quotes at checkout and simple label generation. The 15 price-related praises are consistent and recent. The main risks are reliability and support: several 2022-2024 reviewers lost checkout rates during outages without warning, and the developer's replies promise follow-up but no reviewer confirms a fix. If you ship multi-item orders in several boxes, or need per-product dimensions for a large catalog, the reviews say the dimension handling is weak. Check the billing and overage terms before upgrading from the free plan, and have a fallback flat rate configured in case quotes fail.
Fair evidence. 61 reviews, all from Brazil, with a detailed negative core. About half of the recent reviews are a short-text burst that looks solicited, and several complaint themes rest on 1-3 reviews. Whether the outages are truly resolved cannot be confirmed from reviews alone.
Right for
- Brazilian Shopify stores that want Correios plus several transportadora quotes at checkout at lower freight prices (2353, 3102, 7115)
- Stores new to shipping that want quick setup and label generation (3889, 1180, 3658)
- Stores that need to block or restrict delivery options by region (1182, 3884)
- Merchants with mostly single-parcel orders, where one set of dimensions per order is enough (8275)
Wrong for
- Stores that sell multi-item orders and need separate box dimensions on each label (8275)
- Stores with large catalogs that must load per-product dimensions in bulk; variant metafields can only be filled manually or in batches of 35 (3635)
- Stores for whom losing checkout rates for even a few hours is unaffordable and that need fast phone or chat support (9524, 1281041, 2538)
- Merchants who want to use their own Correios contract on the free plan (7980)
- High-volume shippers (one reviewer says manual label issuing breaks down above ~50 items/day) (5576)
- Stores outside Brazil; all 61 reviews are from Brazil
What will annoy you
Support slow, email-only, or unhelpful (including refund refused on a label problem): 8 reviews, steady, last seen 2026-04.
How the developer behaves when it breaks
Replies to most negative reviews within days, but with templated apologies ("acionamos nosso time... entrará em contato") and no concrete fix. The 2022 outage reply blames Black Friday server prep and promises it will rarely recur (7542), yet a later reviewer reports more outages and no notice (4801). The reply to 9076 says the issue is not the app's. No reviewer confirms a resolution. The two newest negatives (3635, 0071) and the 2026 2★ (5293) have no reply. Positive reviews get quick, friendly replies.
What goes wrong 8 recurring themes
- App outages leave checkout with no shipping rates, and customers are not told 4 reviews fading, last seen 2023-05
“já saiu do ar várias vezes, deixando o nosso site sem cálculo de frete” review 9524
- Rates or delivery times missing or erroring at checkout (CORS error, calculation not working, delivery deadlines not shown) 3 reviews fading, last seen 2024-12
“aparece um "ERRO CORS" ou outros erros, e não finaliza a venda” review 1041
- Support slow, email-only, or unhelpful (including refund refused on a label problem) 8 reviews steady, last seen 2026-04
“Péssimo suporte e atendimento.” review 0071
- Package dimensions: one set per order, metafields only at variant level, metafield products not found 3 reviews steady, last seen 2025-12
“para lojas com muitos produtos anunciados, informar as dimensões é praticamente impossível financeiramente” review 3635
- Label printing / processing problems (Zebra print quality that Correios may reject, label the carrier could not process) 2 reviews steady, last seen 2026-04
“a etiqueta ficar com baixa qualidade o que pode ocasionar dos correios não aceitar (já ocorreu conosco)” review 2174
- Unexpected charges after install (monthly fee plus overage) 1 review fading, last seen 2025-03
“Após integrar, surgem cobranças inesperadas e fora do que foi divulgado.” review 0431
Also 0431 - Tracking codes and order import not syncing automatically into Shopify; manual label issuing 2 reviews fading, last seen 2023-08
“Integração de rastreamento dos pedidos na Shopify não existe.” review 5576
- Own Correios contract not usable on the free plan 1 review fading, last seen 2023-08
“meu unico problema é nao conseguir integrar meu contrato dos correios no plano gratuito” review 7980
Also 7980
What it does well 5 themes
- Low freight prices / discounts versus other quote services 15 reviews
“o valor do frete é o mais barato que encontrei” review 2353
- Several carrier quotes at checkout, including Correios and regional transportadoras 9 reviews
“me traz mais de 6 cotações, muito ágil e sempre os melhores preços” review 3102
- Easy install, setup and label generation 9 reviews
“Simples de configurar e resolveu toda a parte de frete” review 1180
- Freight rules and delivery-area restrictions 4 reviews
“mapear áreas com restrição de entrega e bloquear automaticamente opções que não se aplicam” review 1182
- Support praised as fast and human by many reviewers (contradicted by the negative reviews below) 9 reviews
“a melhor parte é o suporte que é rápido e humanizado” review 5189
Red flags
- Billing surprise: one merchant reports a $40 charge after uninstalling, then $89 overage the next month, then $40 overage after downgrading to the $19 plan. The charges differed from what was quoted before integration. One report only, but specific. 0431
- Silent breakage: outages remove shipping rates from checkout, and merchants say they only learn of it from customer complaints. One reports a ~90% sales drop with CORS errors, and one reports lost ad spend during downtime. 9524 7542 4801 1041
- Support access: several reviewers say email is the only channel after paying. The latest negative review (2026-04) reports a refused refund on a label the carrier could not process, with no developer reply. 5284 2538 1041 0071
- Per-order dimensions: orders with several items need combined dimensions on one label. Shipping each item separately is reported to multiply freight cost (one reviewer's example: R$20 becomes R$100). 8275
Trend
The last 12 months have 22 reviews versus 14 in the prior 12, and the negative share is 13.6% versus 26% overall. That improvement is flattered by the Nov 2025 cluster of short 5★ reviews. The outage complaints (2022 to May 2023) have not reappeared, though checkout quote failures were still reported through Dec 2024. Recent negatives have changed character: billing surprise (2025-03), multi-box and metafield dimension limits (2025-05, 2025-12), and refused refund and support (2026-04). Nothing recent says outages are fixed, but nothing recent reports them either.
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