Comparisons / Blind-tested October 31, 2026
For decision decks you need to send as they are, Claude and Codex with Super Document Skills won every blind pair. Gamma looks busy and finished, but it filled the gaps in the notes with numbers of its own.
Would a blind reviewer send it as it is?
We gave Gamma and Super Document Skills the same two decision-deck requests and notes. A blind reviewer would send Gamma’s decks as they are in 0 of 8 pairings, and found invented numbers and a broken layout in all 8. It would send the skill’s decks 8 of 8 times, from Claude and from Codex, and picked the skill’s deck in every pair.
01 / At a glance
| Feature | Gamma | Super Document Skills |
|---|---|---|
| What it is | An AI web app for presentations, documents, websites and social posts | A free skill set for Claude Code and Codex |
| Where you make the deck | In Gamma’s app from a prompt or an imported file. Gamma also connects to Claude and ChatGPT through an MCP connector, and has an API. | Inside the agent you already use, from your notes, files and context |
| Price | Free plan with 400 credits at signup (our decks used about 30 each) and up to 10 slides per prompt. Paid plans from $9 a month. | Free and open source (MIT) |
| Output | Gamma cards that scroll when they run long. PDF, PowerPoint, PNG and Google Slides export, including on the free plan. | An HTML deck: present in a browser, print to PDF or publish as a private or shared link |
| Sticks to your numbers | Not in our test: the reviewer found figures that weren’t in the notes in 8 of 8 pairings, including two made-up charts | Every number comes from your notes or is worked out from them; the reviewer found nothing invented in 8 of 8 |
| Checks its own slides | Not that we saw: garbled text inside AI pictures, a cut-off chart label and slides taller than the screen | A checker screenshots every slide and the agent fixes overflow, one-word lines and unlabeled charts |
| Length | 10 slides at the default, even when the request asked for 4 or 5 | As long as the request asks: 5 slides for the 4-or-5-slide request |
| Look | AI illustrations, cards and icons on every slide, from a theme you pick | Any style you describe; your own template and layout win |
| Editing | Visual editor and AI edits in the app | Ask your agent, or edit the HTML |
02 / Blind test results
| What the reviewer found | Gamma | Claude + skill | Codex + skill |
|---|---|---|---|
| Would send as it is | 0 of 8 | 4 of 4 | 4 of 4 |
| Picked to send, of the pair | 0 of 8 | 4 of 4 | 4 of 4 |
| Looks better, of the pair | 0 of 8 | 4 of 4 | 4 of 4 |
| States something not in the notes | 8 of 8 | 0 of 4 | 0 of 4 |
| Broken layout | 8 of 8 | 0 of 4 | 0 of 4 |
| Looks like a generic template | 8 of 8 | 0 of 4 | 0 of 4 |
| Working notes left in | 8 of 8 | 0 of 4 | 1 of 4 |
Gamma’s build-or-buy deck charts a build cost of about $80K that isn’t in the notes and labels it “illustrative”. On that chart, building looks cheaper than buying at scale, which works against the deck’s own recommendation to buy.
Where Gamma did well: every option and both sides got a slide, and its risk slide answers the platform lead’s ranking-control argument with a mitigation. The reviewer never called it plain or bare.
The same Codex decks with the skill were sendable 2 of 4 times in our SlideSpeak test and 4 of 4 here. A model reviewer varies; the Claude decks were 4 of 4 both times.
03 / Strengths
04 / Which to use
You want a polished visual deck fast from a short prompt, you need PowerPoint or Google Slides files, and you’ll check every number before you present it.
Your deck asks for a decision and the numbers have to be right: you already use Claude Code or Codex and want a deck you can send as it is.
05 / Method
06 / Questions
Yes. Super Document Skills is a free, open-source skill set for Claude Code and Codex. Your agent makes the deck from your own notes, checks every slide, and you can present it in a browser, print it to PDF or publish it as a link. In our blind test a reviewer would send the skill’s decks 8 of 8 times, and none of Gamma’s as they were.
Gamma offers an MCP connector for Claude and ChatGPT and an API, so Claude can ask Gamma for a deck; Gamma then generates it on its own service. Super Document Skills works the other way: Claude itself writes the deck, following a tested method, and can use everything in your conversation and files.
In our test it added figures that weren’t in the notes to both decks: a revenue chart for the pricing options and a build cost of about $80K for build or buy, both labelled illustrative. The reviewer flagged invented content in all 8 pairings. Check every number in an AI deck against your source before you present it.
No. It makes HTML decks, which present in any browser, print to PDF and can be published as a private or shared link with share/artifacts. If you must hand over a .pptx or Google Slides file, Gamma exports both, even on its free plan.
A Claude model acting as a blind reviewer, using the same checklist as our published release test: invented facts, plain or template look, broken layout, wordiness, working notes left in, and whether it would send the deck as it is. No human panel has judged these decks yet.
In Claude Code or Codex:
npx skills add arunai30/super-document-skills --agent claude-code --skill create-html-presentation --copyFor Codex, use --agent codex. Using Claude in the browser? Connect share/artifacts and your agent gets the same deck recipes, then publishes the deck as a private or shared link.
Sources: Gamma (free plan, used 31 October 2026) · Gamma pricing · Gamma integrations · Our decision deck release test · Super Document Skills on GitHub