Chat and everyday writing

ChatGPT

Made by OpenAI

OpenAI's assistant for writing, rewriting and rehearsing, with GPT-6 rolling out in October 2026.

What it is

ChatGPT is the one to start with if you only ever learn one of these. It is a general assistant: you type what you want in plain English and it writes back. For the work this library is about — tailoring a resume, turning notes into prose, rehearsing answers out loud — it is the strongest of the free options and the one whose habits are easiest to learn.

Its real strength is following a long, fussy instruction without losing the thread. You can give it your actual resume, the actual posting, and three rules about tone, and it will respect all of them. Its real weakness is confidence: when it doesn't know something it invents something plausible, in the same steady voice it uses for facts.

OpenAI announced GPT-6 in ChatGPT on October 7. GPT-6 Sol rolls out to Plus, Pro, Business and Enterprise first; GPT-6 Luna follows for Free and Go from October 8. Free-plan usage and tool limits still apply, and the rollout may not reach every account immediately.

The release introduces what OpenAI calls Intelligent UI: answers that can include charts, forms and small interactive tools. ChatGPT access is separate from API billing and from the older endpoints currently runnable inside this library.

Check any fact, name, date or number before you send it to an employer.

Published price

FreeGPT-6 Luna available since its October 8 rollout; usage and tool limits apply$0/month
GoMay include ads. OpenAI leaves the figure off its own page and shows it at checkout; $8 is the figure reported by CloudZero's price tracking, September 2026$8/month
Plus$20/month
Pro$100/month, or $200/month for the higher usage tier
Business$25/seat billed monthly, two-seat minimum$20/seat/month billed annually

OpenAI localizes and A/B-tests these figures and does not print the Go price on the page, so confirm at checkout before paying.

Source: OpenAI's pricing page · Last checked 8 October 2026

Benchmarks

The published figures for ChatGPT, copied exactly as their sources give them and checked 29 September 2026. Each one names the test, who ran it and when, and says when the number comes from the maker rather than an independent tester.

Terminal-Bench 4.058.2% (±2.8)
share of real command-line tasks completed unaided · tested: GPT-6 Astra, max reasoning — ranked 1st
Terminal-Bench / Snorkel · 29 August 2026 · independent
Artificial Analysis Intelligence Index v4.3.253
combined score across ten reasoning and knowledge tests · tested: GPT-6 Astra, max reasoning — ranked 7th of 216 models
Artificial Analysis · 28 September 2026 · independent
Measured at 63.6 tokens per second output speed.
LMArena Elo (style-controlled)1,486
blind head-to-head preference votes from the public · tested: GPT-5.6 Sol, extra-high reasoning
Model Gauntlet (LMArena data) · 20 July 2026 · independent

OpenAI doesn't publish comparable per-model figures on a single page, so these come from independent testers. They test the top reasoning setting, which is not what the free tier gives you.

Figures copied from the sources above, checked 29 September 2026.

Where to read today's numbers

Scores move, so these are the boards that keep them current.

LMArena leaderboardIndependent
Ranks models by blind head-to-head votes from the public. Good for a feel for general quality, weak on specialist work.
Artificial AnalysisIndependent
Independent testing of quality, speed and price per million tokens across hosted models.
Vals AI benchmarksIndependent
Independent evaluations on real professional tasks — law, finance, tax, medicine — rather than vendor demos.

How it performs, in my experience

OpenAI's general assistant for writing, rewriting and conversation. Its October 7 GPT-6 announcement introduces Intelligent UI: answers that can include charts, forms and small interactive tools. GPT-6 Sol rolled out to eligible paid plans first; GPT-6 Luna available in Free and Go since its October 8 rollout.

Free value
4 / 5
How much you get without paying.
Performance
5 / 5
How well it does its main job.
Range of uses
5 / 5
How many different jobs it suits.

The safest first choice for writing work; the free tier is limited but real. These scores are my own judgment, not a measurement — the benchmark links above are the independent version.

Prompting it from this site

You can run this here

Three settings are wired up — quick, middle and thinking — and they run on this site's own AI credits, not your ChatGPT plan.

Use it for

Tailoring a resume to a specific posting
Turning rough notes into clean prose
Practicing interview answers out loud

Running it yourself

Hosted only — nothing to install

ChatGPT's models are closed — there are no weights to download, so nothing runs on your own machine. What you can run locally is code that calls it over the internet.

What you need first

Python 3.8 or newer (or Node.js 18+)
A paid OpenAI API key — the ChatGPT subscription does not include API use

Step by step

1.Install the official client
```
pip install openai
```
2.Put your key in the environment
```
export OPENAI_API_KEY=sk-...
```

3.Check it answers

python -c "from openai import OpenAI; print(OpenAI().responses.create(model='<model id from their docs>', input='hello').output_text)"

API use is billed per token, separately from any ChatGPT plan. If you want something that runs offline, look at the open models group instead.