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Threadbox vs CustomGPT

CustomGPT is strong at what it focuses on: accurate, citation-backed answers over large collections of documents and pages. It is a knowledge assistant first.

Threadbox is a support agent that also needs to act, escalate and work across channels. This comparison helps you decide which problem you are actually solving.

  • UK/EU hosted
  • UK GDPR ready
  • Encrypted at rest and in transit
  • Companies House 00838986

Last updated

Verdict

TL;DR

CustomGPT focuses on accurate answers over large document sets. Threadbox adds live-data actions, more channels and a support desk for teams handling customer requests.

Which should you choose?

Choose Threadbox if…

  • You need live-data actions and deterministic webhooks, not only answers
  • You want WhatsApp, Slack and email with a shared inbox
  • You want UK/EU hosting and GBP billing

Choose CustomGPT if…

  • You need an internal or public knowledge assistant over large document sets
  • Web and API cover the channels you need
  • Customer support workflows are handled elsewhere

At a glance

Feature comparison between Threadbox and CustomGPT
CapabilityThreadboxCustomGPT
Agent
Train on website, files and Q&A
Choice of OpenAI, Anthropic and Google modelsPartial
Custom actions that call your APIsLimited
Deterministic regex webhooks (no LLM in the loop)Not advertised
Guardrails: blocked topics, injection and leak checks
Playground with compare mode and saved scenariosNot advertised
Channels & widgets
Website widget with streaming replies
Slack, WhatsApp and emailEmail from Starter, WhatsApp from Growth, Slack on BusinessWeb + API
Rich widgets: cards, buttons, forms, status cardsBasic
Lead capture with triggers and CSV export
Team
Shared inbox with human takeoverNot advertised
Escalation rules: sentiment, keywords, fallbacksNot advertised
Roles: owner, admin, agent, viewerPartial
Ask-your-data assistant (Backstage)Not advertised
Support desk
Threads with references, custom fields and statusesNot advertised
Response targets with business hoursNot advertised
Rules and skills-based routingNot advertised
Customer portal with guides and communityNot advertised
Phone, SMS and social channelsNot advertised
Business
UK/EU hosting by defaultNot stated
Pricing in GBP with VAT invoicesNot advertised
Per-resolution feesNoneNone
Free seats for viewers and contributorsNot advertised
Human support from the team who built itEmail

CustomGPT is a trademark of its respective owner. Comparison based on public documentation as of 19 October 2026. “Not advertised” means we could not find it in CustomGPT’s public material. Spotted something out of date? Tell us.

Pricing in GBP

Threadbox

GBP, excluding VAT, billed monthly

  • Free50 conversations a month£0/month
  • Starter500 conversations a month£29/month
  • Growth2,000 conversations a month£99/month
  • Business10,000 conversations a month£349/month

No per-resolution fees. Extra conversations in blocks of 100, up to a spend cap you set. Full pricing

CustomGPT

Published in USD, with an approximate GBP conversion

  • Standard$89/month billed annually; 10 agents, 1,000 queries≈ £74/month$99/month
  • Premium$449/month billed annually; 25 agents, 5,000 queries≈ £374/month$499/month
  • EnterpriseCustom

Source: CustomGPT pricing page, checked on . GBP converted at the 16 October 2026 rate.

How to switch

  1. 1Paste the same URLs and upload the same documents
  2. 2Add Q&A pairs for edge cases
  3. 3Create an action for your top live-data question
  4. 4Embed the widget or connect Slack
  5. 5Set escalation rules and invite your team

Read the full CustomGPT alternative guide or browse all alternatives.

Knowledge depth

CustomGPT handles large corpora well with citations and anti-hallucination controls. Threadbox grounds answers in retrieved chunks, shows sources in the Playground and lets you set guardrails and a fallback message. For typical support knowledge bases the difference is small.

Actions, webhooks and widgets

Threadbox calls your APIs through custom actions and deterministic regex webhooks and renders results as cards, buttons and forms. CustomGPT is primarily answer-oriented.

Try it on your own website

Paste your URL. We crawl it and hand you a working agent in minutes. Free plan, no card.

Support operations

Threadbox includes a shared inbox, rule-based escalation, human takeover and analytics across web, Slack, WhatsApp and email. CustomGPT does not aim to be a support desk.

Hosting and billing

Threadbox is UK/EU hosted with GBP VAT invoicing. CustomGPT prices in USD.

FAQ

Frequently asked questions

Yes. Sources are chunked and embedded with live index status and reindex in the background when edited.

Keep exploring

Knowledge plus action

Accurate answers and live data, in one agent your team can supervise.

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  • UK/EU hosted
  • UK GDPR ready
  • Encrypted at rest and in transit
  • Companies House 00838986